// C語言除錯高手	Learning C by debugging

/* ex1-5a.c */
main(){
	int num=30;
	printf("指定 num 的初值為 30\n");
	printf("num = %d\n",num);
}

/* ex1-5b.c */
main(){
	int i_num1 = 300;
	int i_num2;
	double d_num = 33.5;
	char c_letter1 = 'a', c_letter2 = 'b';
	printf("i_num1 = %d\n", i_num1);
	printf("i_num2 = %d\n", i_num2);
	printf("d_num = %f\n", d_num);
	printf("c_letter1 = %c\n", c_letter1);
	printf("c_letter2 = %c\n", c_letter2);
}

/* ex2-1a.c */
main(){
	printf("標準的輸出與輸入函數計有:\n");
	printf("printf () 和 scanf()\n");
}

/* ex2-1b.c */
main(){
	int number = 8;
	char letter = 'z';
	/* %d、%c為格式特定字 */
	printf("1 加 1 是 %d\n", 2);
	printf("1 加 7 是 %d\n", number);
	printf("%c 是第一個英文字母\n", 'a');
	printf("%c 是最後一個英文字母\n", letter);
}

/* ex2-1c.c */
main(){
	char letter1 = 'a';
	char letter2 = 'b';
	char letter3 = 'c';
	char letter4 = 't';
	printf("%c %c %c are known by everyone\n", letter1, letter2, letter3);
	printf("I have a %c%c%c\n", letter3, letter1, letter4);
}

/* ex2-1d.c */
main(){
	int i_num1= 100;
	printf("100%% orange juice\n");

	/* 使用有關整數的格式特定字輸出 */
	printf("輸出 100 使用 %%d: %d\n", i_num1);
	printf("輸出 100 使用 %%x: %x\n", i_num1);
	printf("輸出 100 使用 %%o: %o\n", i_num1);
}

/* ex2-1e.c */
main(){
	float f_number = 123.456;
	double d_number = 123.456;
	printf("f_number = %f\n", f_number);
	printf("d_number = %f\n", d_number);
}

/* ex2-1f.c */
main(){
	printf("We don\'t have enough time\n");
	printf("Everybody say \" Later is better than never\"\n");
	printf("Computer is powerfuk\bl\n");
	printf("    can make it\rYou\n");
	printf("Failure \151\163 the mother \x6f\x66 success\n");
}

/* ex2-1g.c */
main(){
	char letter = 'a';
	printf("|%c| using %%c\n", letter);
	printf("|%10c| using %%10c\n", letter);
	printf("|%-10c| using %%-10c\n", letter);
}

/* ex2-1h.c */
main(){
	int number1 = 123;
	double number2 = 123.456;
	printf("使用 %%d--------|%d|\n", number1);
	printf("使用 %%10d------|%10d|\n", number1);
	printf("使用 %%-10d-----|%-10d|\n", number1);
	printf("使用 %%2d-------|%2d|\n", number1);
	printf("使用 %%10.2f----|%10.3f|\n", number2);
	printf("使用 %%.2f------|%.2f| \n", number2);
}

/* ex2-1i.c */
main(){
	double num1=123.456, num2=12.34, num3=12.345 ;
	double num4=4.456,   num5=45.67, num6=456.789 ;
	printf("%f %f %f\n", num1, num2, num3);
	printf("%f %f %f\n", num4, num5, num6);

	printf("\n\n使用欄位寬...\n");
	printf("%8.3f %8.3f %8.3f\n", num1, num2, num3);
	printf("%8.3f %8.3f %8.3f\n", num4, num5, num6);
}

/* ex2-2a.c */
main(){
	int x;
	printf("請輸入一整數值: ");
	scanf("%d", &x);  /* &為位址運算子 */
	printf("您輸入的整數是 %d\n", x);
}

/* ex2-2b.c */
main(){
	int x;
	printf("請輸入一整數值: ");
	scanf("%d", x);
	printf("您輸入的整數是 %d\n", x);
}

/* ex2-2c.c */
main(){
	int i_num1;
	char ch;
	float f_num;
	double d_num;
	/* 要求輸入各種格式的值 */
	printf("請輸入一字元: ");
	scanf("%c", &ch);

	printf("請輸入float浮點數: ");
	scanf("%f", &f_num);
	printf("請輸入double浮點數: ");
	scanf("%lf", &d_num);

	/* 將輸入結果輸出至螢幕上 */
	printf("---------------------------------------------\n");
	printf("您輸入的字元是 %c\n", ch);
	printf("您輸入的float浮點數是 %f\n", f_num);
	printf("您輸入的double浮點數是 %f\n", d_num);
}

/* ex2-2d.c */
main(){
	int hour, min, sec;
	int year, month, days;
	char letter1, letter2;
	printf("請輸入兩個字元，中間以空白隔開: ");
	scanf("%c %c", &letter1, &letter2);   /* 輸入兩個字元 */
	printf("請輸入現在的時間? (hour:min:sec): ");
	scanf("%d:%d:%d", &hour, &min, &sec);  /* 輸入時間 */
	printf("請輸入現在的日期? (month-day-year): ");
	scanf("%d-%d-%d", &month, &days, &year);  /* 輸入日期 */
	printf("\n");
	printf("兩個字元分別為: %c 和 %c\n", letter1, letter2);
	printf("現在時間是: %d 點 %d 分 %d 秒\n", hour, min, sec);
	printf("現在的日期是: 西元 %d %d月 %d日\n", year, month, days);
}

/* ex3-2a.c */
main(){
	printf("15 + 7 = %d\n", 15+7);
	printf("10 - 2 = %d\n", 10-2);
	printf("20 * 5 = %d\n", 20*5);
	printf("10 / 2 = %d\n", 10/2);
	printf("20 %% 7 = %d\n", 20%7);
}

/* ex3-2b.c */
main(){
	printf("20/3 = %d\n", 20/3);
	printf("20/3. = %f\n", 20/3.);
}

/* ex3-2c.c */
main(){
	char c_letter;
	c_letter = 'a' + 'd' - 'b';
	printf("a + d - b = %c\n", c_letter);
}

/* ex3-3a.c */
main(){
	int num1, num2;
	num1 = 60;
	num2 = 30;
	printf("num1 = %d, num2 = %d\n", num1, num2);
	num1 -= num2;
	printf("num1-=num2 => num1 = %d, num2 = %d\n", num1, num2);
	num1 /= num2;
	printf("num1/=num2 => num1 = %d, num2 = %d\n", num1, num2);
	num1 += num2;
	printf("num1+=num2 => num1 = %d, num2 = %d\n", num1, num2);
	num1 *= num2;
	printf("num1*=num2 => num1 = %d, num2 = %d\n", num1, num2);
	num1 %= num2;
	printf("num1%%=num2 => num1 = %d, num2 = %d\n", num1, num2);
}

/* ex3-4a.c */
main(){
	int num = 20, total = 0;
	total = ++num + 30;
	printf("total = %d, num = %d\n", total, num);
	total = 0;
	num = 20;
	total = num++ + 30;
	printf("total = %d, num = %d\n", total, num);
}

/* ex3-5a.c */
main(){
	int num1, num2;
	num1 = 90;
	num2 = 80;
	printf("%d < %d: %d\n", num1, num2, num1 < num2);
	printf("%d <= %d: %d\n", num1, num2, num1 <= num2);
	printf("%d > %d: %d\n", num1, num2, num1 > num2);
	printf("%d >= %d: %d\n", num1, num2, num1 >= num2);
	printf("%d == %d: %d\n", num1, num2, num1 == num2);
	printf("%d != %d: %d\n", num1, num2, num1 != num2);
}

/* ex3-6a.c */
main(){
	int num1 = 50, num2 = 70, num3 = 60, bool;
	printf("num1 = %d\n", num1);
	printf("num2 = %d\n", num2);
	printf("num3 = %d\n", num3);
	bool = num2 > num1 && num2 > num3;
	printf("num2 > num1 && num2 > num3 => %d\n", bool);
	bool = num2 > num1 && num1 > num3;
	printf("num2 > num1 && num1 > num3 => %d\n", bool);
	printf("-------------------------------------------\n");
	bool = num1 > num2 || num2 > num3;
	printf("num1 > num2 || num2 > num3 => %d\n", bool);
	bool = num1 > num2 || num3 > num2;
	printf("num1 > num2 || num3 > num2 => %d\n", bool);
	printf("-------------------------------------------\n");
	bool = !(num1 > num3 && num2 > num3);
	printf("!(num1 > num3 && num2 > num3) => %d\n", bool);
	bool = !(num1 > num2 || num3 > num1);
	printf("!(num1 > num2 || num3 > num1) => %d\n", bool);
}

/* ex3-7a.c */
main(){
	short int i = 15;
	short int j = 11;
	printf("i & j = %hx\n", i & j);
	printf("i | j = %hx\n", i | j);
	printf("i ^ j = %hx\n", i ^ j);
	printf("~i = %hx\n", ~i);
}

/* ex3-7b.c */
main(){
	short int a = 8;
	short int b=-8;
	printf("a = %d\n", a);
	printf("a << 1 = %d\n", a << 1);
	printf("a << 2 = %d\n", a << 2);
	printf("a << 3 = %d\n", a << 3);
	printf("a >> 1 = %d\n", a >> 1);
	printf("a >> 2 = %d\n", a >> 2);
	printf("a >> 3 = %d\n", a >> 3);

	printf("\n");
	printf("b = %d\n", b);
	printf("b << 1 = %d\n", b << 1);
	printf("b << 2 = %d\n", b << 2);
	printf("b << 3 = %d\n", b << 3);
	printf("b >> 1 = %d\n", b >> 1);
	printf("b >> 2 = %d\n", b >> 2);
	printf("b >> 3 = %d\n", b >> 3);
}

/* ex3-8a.c */
main(){
	double d_num1 = 5.7, d_num2 = 7.5;
	int i_num3, i_num4;
	i_num3 = d_num1 + d_num2;
	i_num4 = (int)d_num1 + (int)d_num2;  /* 將double轉為int */
	printf("num is %d before transferring type\n", i_num3);
	printf("num is %d after transferring type\n", i_num4);
}

/* ex3-8b.c */
main(){
	int i_num1 = 2147483647, i_num2 = 1;
	double d_num3, d_num4;
	d_num3 = i_num1 + i_num2;

	/* 將int轉型為double */
	d_num4 = (double) i_num1 + (double) i_num2;
	printf("num is %.0f before transferring type\n", d_num3);
	printf("num is %.0f after transferring type\n", d_num4);
}

/* ex4-1a.c */
main(){
	int score;
	printf("若分數大於等於60分，則再加10分\n");
	printf("請輸入您的分數: ");
	scanf("%d", &score);
	if (score >= 60)
		score += 10;
	printf("您最後的分數為 %d\n", score);
}

/* ex4-2a.c */
main(){
	int score;
	printf("若分數大於等於60分，則再加10分，否則加5分\n");
	printf("請輸入您的分數: ");
	scanf("%d", &score);
	if (score >= 60)
		score += 10;
	else
		score += 5;
	printf("您最後的分數為 %d\n", score);
}

/* ex4-2b.c */
main(){
	int num = 200;
	if (num = 100) /* =為指定運算子 */
		printf("num is 100\n");
	else
		printf("num is 200\n");
}

/* ex4-2c.c */
main(){
	int num = 200;
	if (num == 100) /* ==才是等號運算子*/
		printf("num is 100\n");
	else
		printf("num is 200\n");
}

/* ex4-2d.c */
main(){
	int num;
	printf("正確的數字範圍是從 100 到 200\n");
	printf("請輸入一數字: ");
	scanf("%d", &num);
	if (num >= 100 && num <= 200)
		printf("此為正確的數字!!\n");
	else
		printf("此為不正確的數字!!\n");
}

/* ex4-2e.c */
main(){
	int num;
	printf("請輸入一整數: ");
	scanf("%d", &num);
	if (num >= 0){
		printf("%d 是大於或等於 0\n", num);
		printf("所以 %d 是正整數\n", num);
	}else{
		printf("%d 是小於 0\n", num);
		printf("所以 %d 是負數\n", num);
	}
}

/* ex4-2f.c */
main(){
	int score;
	printf("Please input a score: ");
	scanf("%d", &score);
	if (score >= 60)
		if (score <= 80)
			score = score + 10;
		else
			score = score + 5;
	printf("score = %d\n", score);
}

/* ex4-2g.c */
main(){
	int score;
	printf("請輸入您的分數: ");
	scanf("%d", &score);
	if (score >= 60){
		if (score <= 80)
			score = score +10;
	}else
		score= score +5;
	printf("您最後的分數為 = %d\n", score);
}

/* ex4-3a.c */
main(){
	int num1, num2, big;
	printf("請輸入兩個整數: ");
	scanf("%d %d", &num1, &num2);

	/*將較大的數存放於big變數 */
	big = (num1 > num2) ? num1 : num2;
	printf("最大數為 %d\n", big);
}

/* ex4-3b.c */
main(){
	int num1, num2, big;
	printf("請輸入兩個整數: ");
	scanf("%d %d", &num1, &num2);

	/*將較大的數存放於big變數 */
	if (num1 > num2)
		big = num1;
	else
		big = num2;
	printf("最大數為 %d\n", big);
}

/* ex4-4a.c */
main(){
	int num;
	printf("請輸入一整數: ");
	scanf("%d", &num);
	if (num > 0)
		printf("%d 是一正數\n", num);
	else if (num < 0)
		printf("%d 是一負數\n", num);
	else
		printf("%d 是0\n", num);
}

/* ex4-4b.c */
main(){
	int level;
	printf("請問你是幾年級學生(1-5): ");
	scanf("%d", &level);
	if (level == 1)
		printf("你是大一新生\n");
	else if (level == 2)
		printf("你是大二學生\n");
	else if (level == 3)
		printf("你是大三學生\n");
	else if (level == 4)
		printf("你是大四學生\n");
	else if (level == 5)
		printf("你是研究生\n");
	else
		printf("錯誤的代碼!!\n");
}

/* ex4-5a.c */
main(){
	/* switch敘述不使用break; */
	int num;
	printf("請輸入一整數: ");
	scanf("%d", &num);
	switch (num){
	case 1:
		printf("友子\n");
	case 2:
		printf("阿嘉\n");
	case 3:
		printf("茂伯\n");
	case 4:
		printf("馬拉桑\n");
	default:
		printf("你不是海角七號的演員\n");
	}
}

/* ex4-5b.c */
main(){
	/* switch敘述不使用break; */
	int num;
	printf("請輸入一整數: ");
	scanf("%d", &num);
	switch (num){
	case 1:
		printf("友子\n");
		break;
	case 2:
		printf("阿嘉\n");
		break;
	case 3:
		printf("茂伯\n");
		break;
	case 4:
		printf("馬拉桑\n");
		break;
	default:
		printf("你不是海角七號的演員\n");
	}
}

/* ex4-5c.c */
main(){
	/*	修改範例4-4b的else-if敘述更改為使用switch敘述
	    將int改為char型態，示範switch在字元常數下的用法 */
	char level;
	printf("請問你是幾年級的學生(1…5): ");
	scanf("%c", &level);
	switch (level){
	case '1':
		printf("你是大一新生\n");
		break;
	case '2':
		printf("你是大二學生\n");
		break;
	case '3':
		printf("你是大三學生\n");
		break;
	case '4':
		printf("你是大四學生\n");
		break;
	case '5':
		printf("你是研究生\n");
		break;
	default:
		printf("錯誤的代碼!!\n");
	}
}

/* ex4-5d.c */
main(){
	char ch;
	printf("please input a character: ");
	scanf("%c", &ch);
	switch (ch){
	case 'y':
	case 'Y':
		printf("one more\n");
		break;
	case 'n':
	case 'N':
		printf("no more\n");
		break;
	default:
		printf("over\n");
	}
}

/* ex5-1a.c */
main(){
	int num;
	for (num = 0; num <= 5; num++){
		printf("Num is %d\n", num);
	}
}

/* ex5-1b.c */
main(){
	int num = 0; /* 設定num初值為0 */
	for ( ; num <= 5; num++) /* 省略初值的設定 */{
		printf("Num is %d\n", num);
	}
}

/* ex5-1c.c */
main(){
	int num = 0;
	for ( ; num <= 5; ){
		printf("Num is %d\n", num);
		num++;
	}
}

/* ex5-1d.c */
main(){
	int num = 0;
	for ( ; num <= 5; )
		printf("Num is %d\n", num);
	num++;
}

/* ex5-1e.c */
main(){
	/* 將範例5-1a的設定初值、條件判斷式及更新敘述省略 */
	int num = 0;
	for ( ; ; ){
		if (num > 5) /* 若num 大於5，則執行break，以結束for迴圈 */
			break;
		printf("Num is %d\n", num);
		num++;
	}
}

/* ex5-1f.c */
main(){
	/* 要求使用者不斷輸入數字，直到數字為負 */
	int num = 0;
	for (;num >= 0; ){
		printf("請輸入一整數(當此數為負時，將結束迴圈): ");
		scanf("%d", &num);
	}
	printf("輸入結束!!");
}

/* ex5-1g.c */
main(){
	int i, total = 0;
	for (i = 1; i<=100; i++)
		total += i;
	printf("1 + 2 + 3 + … + 100 = %d\n", total);
}

/* ex5-2a */
main(){
	int num = 0;
	while (num >= 0){
		printf("請輸入一整數(當此數為負時，將結束迴圈): ");
		scanf("%d", &num);
	}
	printf("結束");
}

/* ex5-2b.c */
main(){
	int i = 1, total = 0;
	while (i<=100){
		total += i;
		i++;
	}
	printf("1 + 2 + 3 + … + 100 = %d\n", total);
}

/* ex5-2c.c */
main(){
	/* 要求使用者輸入單字，計算字數 */
	char letter;
	int count = 0;
	printf("請輸入一行文字: ");
	scanf("%c", &letter);
	while (letter != '\n'){
		count++;
		scanf("%c", &letter);
	}
	printf("此行共有 %d 字\n", count);
}

/* ex5-3a.c */
main(){
	int height;
	double inch;
	do{
		printf("請問您的身高幾公分? ");
		scanf("%d", &height);
	} while (height < 0); /* 身高若負，則要求重新輸入 */
	height /= 2.54;       /* 將公分轉為公吋 */
	printf("你的身高是 %d 呎 %d 吋\n", height/12, height%12); /*一呎等於12吋 */
}

/* ex5-3b.c */
main(){
	int i = 1, total = 0;
	do {
		total += i;
		i++;
	}while (i<=100);
	printf("1 + 2 + 3 + … + 100 = %d\n", total);
}

/* ex5-3c.c */
main(){
	/* 建立選單，讓使用者輸入選項完成該選項工作 */
	int option, no1, no2;
	/* 此選單有三個功能：1為加法，2為減法，3則跳出程式 */
	do {
		printf("\n");
		printf("1 => 加的運算\n");
		printf("2 => 減的運算\n");
		printf("3 => 結束\n");
		printf("請選擇 (1-3): ");
		scanf("%d", &option);
		switch (option) /* 使用switch選擇敘述來執行各項功能 */{
		case 1:
			printf("請輸入兩個整數: ");
			scanf("%d %d", &no1, &no2);
			printf("%d + %d is %d\n", no1, no2, no1+no2);
			break;
		case 2:
			printf("請輸入兩個整數: ");
			scanf("%d %d", &no1, &no2);
			printf("%d - %d is %d\n", no1, no2, no1 - no2);
			break;
		case 3:
			printf("再見!!");
			break;
		default:
			printf("錯誤的選擇!!\n");
		}
	} while (option != 3); /* 使用者輸入3則結束迴圈 */
}

/* ex5-4a.c */
main(){
	/* 以巢狀for迴圈輸出九九乘法表 */
	int i, j;
	printf("%44s", "<< 九九乘法表 >>\n");
	for (i=1; i<=9; i++) {   /* 此為外迴圈 */
		for (j=1; j<=9; j++)   /* 此為內迴圈 */
			printf("%d*%d=%2d  ", j, i, i*j);
		printf("\n");
	}
}

/* ex5-4b.c */
main(){
	/* 以巢狀for迴圈輸出九九乘法表 */
	int i, j;
	printf("%44s", "<< 九九乘法表 >>\n");
	for (i=1; i<=9; i++) {   /* 此為外迴圈 */
		for (j=1; j<=9; j++)   /* 此為內迴圈 */
			printf("%d*%d=%2d  ", i, j, i*j);
		printf("\n");
	}
}

/* ex5-5a.c */
main(){
	/* 要求輸入一個單字，顯示並計算字元個數 */
	char letter;
	int count = 0;
	printf("請輸入一個單字: ");
	scanf("%c", &letter);
	while (letter != '\n'){
		if (letter == 'a')  /* 若遇到字元為a，則強迫跳離 */
			break;
		if (letter != '\n'){
			count++;
			printf("%c", letter);
		}
		scanf("%c", &letter);
	}
	printf("共有 %d 字元\n", count);
}

/* ex5-5b.c*/
main(){
	int i, num, total=0;
	printf("輸入10 個整數，累加正整數，當輸入的值是負的，則結束迴圈\n");
	for (i=1; i<=10; i++){
		printf("請輸入第 %2d 個整數: ", i);
		scanf("%d", &num);
		if ( num >= 0)
			total += num;
		else
			break;
	}
	printf("Total=%d\n", total);
}

/* ex5-5c.c */
main(){
	/* 要求輸入一個單字，顯示並計算字元個數 */
	char letter;
	int count = 0;
	printf("請輸入一個單字: ");
	scanf("%c", &letter);
	while (letter != '\n'){
		if (letter == 'a') /* 若遇到字元為a，不列入顯示及計算 */{
			scanf("%c", &letter);
			continue;
		}
		if (letter != '\n'){
			count++;
			printf("%c", letter);
		}
		scanf("%c", &letter);
	}
	printf("共有 %d 字元\n", count);
}

/* ex5-5d.c*/
main(){
	int i, num, total=0;
	printf("輸入10 個整數，累加正整數\n");
	for (i=1; i<=10; i++){
		printf("請輸入第 %2d 個整數: ", i);
		scanf("%d", &num);
		if ( num >= 0)
			total += num;
		else
			continue;
	}
	printf("Total=%d\n", total);
}

/* ex5-6a.c */
main(){
	int i = 0, total = 0;
	while (++i <= 100)
		total += i;
	printf("1 + 2 + 3 + … + 100 = %d, i=%d\n", total, i);
}

/* ex5-6b.c */
main(){
	int i = 0, total = 0;
	while (i++ < 100)
		total += i;
	printf("1 + 2 + 3 + … + 100 = %d, i=%d\n", total, i);
}

/* ex5-6c.c */
main(){
	int i=1, total=0;
	do{
		total += i;
	}while (++i <= 100);
	printf("1 + 2 + 3 + … + 100 = %d, i=%d\n", total, i);
}

/* ex5-6d.c */
main(){
	int i=1, total=0;
	do{
		total += i;
	}while (i++ < 100);
	printf("1 + 2 + 3 + … + 100 = %d, i=%d\n", total, i);
}

/* ex6-1a.c */
void output();  /* 函數原型宣告 */
main(){
	printf("呼叫output函數!!\n");
	output();     /* 呼叫output()函數 */
	printf("呼叫結束，over!!\n");
}

/* output()函數的定義 */
void output()
{
	printf("我喜歡iMac\n");
	printf("也喜歡iPod\n");
}

/* ex6-2a.c */
int square();  /* square()的原型宣告 */
main(){
	int ans;
	printf("計算某一整數的平方\n\n");
	ans = square();  /* 用ans接收square()的傳回值 */
	printf("它的平方是 %d\n", ans);
}

/* 定義square()，函數型態為int */
/* 要求輸入一數，之後將此數平方後傳回 */
int square(){
	int num, total;
	printf("請輸入一整數: ");
	scanf("%d", &num);
	total=num*num;
	return  total; /* 將total傳回呼叫函數 */
}

/* ex6-2b.c */
void test();  /* test()的原型宣告 */
main(){
	printf("此程式在測試 return 的作用\n");
	printf("測試開始!!\n");
	test();  /* 呼叫test() */
	printf("測試結束!!\n");
}

/* test()的定義 */
/* 利用for迴圈測試return; 的效力 */
void test()
{
	int i, a, b;
	for (i = 1; i <= 10; i++) /* 會執行10次的for迴圈 */{
		printf("請輸入 a 和 b: ");
		scanf("%d %d", &a, &b);
		if (b == 0)
			return;  /* 當b=0時，執行return; */
		else
			printf("%d/%d=%d\n", a, b, a/b);
		printf("for 迴圈跑了 %d 次\n\n", i);
	}
}

/* ex6-3a.c */
int square(int);  /* square()的原型宣告 */
main(){
	int num, ans;
	printf("計算某一整數的平方\n\n");
	printf("請輸入一整數: ");
	scanf("%d", &num);
	ans = square(num);  /* 用ans接收square()的傳回值 */
	printf("%d 的平方是 %d\n", num, ans);
}

/* 定義square()，函數型態為int */
/* 要求輸入一數，並將此數平方後傳回 */
int square(int n)
{
	int total;
	total=n*n;
	return  total; /* 將total傳回呼叫函數 */
}

/* ex6-3b.c */
void printstar(int);  /* printfstar()的原型宣告 */
main(){
	int num;
	printf("請問要多少個*: ");
	scanf("%d", &num);
	printstar(num);
}

void printstar(int n)
{
	int i;
	for (i=1; i<n; i++)
		printf("*");
	printf("\n");
}

/* ex6-3c.c */
int squAdd(int, int);
void printstar(int);
main(){
	int num1, num2, star, sum;
	printf("此程式在計算兩整數的平方和\n\n");
	printf("請輸入兩個整數: ");
	scanf("%d %d", &num1, &num2);
	/* 傳遞兩個變數num1、num2到squAdd()*/
	/* 使用變數　sum　接收函數傳回值 */
	sum = squAdd(num1, num2);
	printf("請問要多少個*: ");
	scanf("%d", &star);
	printstar(star);
	printf("%d 的平方加　%d 的平方為 %d\n", num1, num2, sum);
	printstar(star);
}

/* 定義squAdd()，函數型態為int，參數為a、b */
/* 計算a、b的平方和後回傳 */
int squAdd(int a, int b)
{
	int ans;
	ans = a * a + b * b;
	return ans;
}

void printstar(int n)
{
	int i;
	for (i=1; i<=n; i++)
		printf("*");
	printf("\n");
}

/* ex6-4a.c */
int number;        /* number是一個全域變數 */
void output();  /* output()的原型宣告 */
main(){
	printf("Please enter a number: ");
	scanf("%d", &number);
	output();
}

/* 定義output()*/
void output()
{
	printf("number is %d\n", number);
}

/* ex6-4b.c */
void input();   /* input()的原型宣告 */
void output();  /* output()的原型宣告 */
main(){
	printf("此程式在測試全域變數\n");
	input();
	output();
}

int array[5];  /* 定義全域變數array陣列 */

/* 定義input()*/
void input(){
	int index;  /* 定義input()的區域變數 */
	for (index = 0; index < 5; index++){
		printf("請輸入 #%d 整數: ", index+1);
		scanf("%d", &array[index]);  /* 使用全域變數做輸入 */
	}
}

/* 定義output() */
void output(){
	int index;  /* 定義output()的區域變數 */
	printf("\n");
	for (index = 0; index < 5; index++) /* 使用全域變數做輸出 */
		printf("array[%d] is %d\n", index, array[index]);
}

/* ex6-4c.c */
int number = 100;  /* 定義全域變數 */
void output();
main(){
	printf("number is %d\n", number);
	output();
}

/* 定義output() */
void output()
{
	int number = 200;  /* 定義區域變數 */
	printf("number is %d\n", number);
}

/* ex6-5a.c */
int factorial(int);
main(){
	int num;
	printf("Please input a number: ");
	scanf("%d", &num);
	printf("Factorial(%d)=%d\n", num, factorial(num));
}

int factorial(int n)
{
	if (n >1)
		return (n * factorial(n-1));
	else
		return 1;
}

/* ex6-5b.c */
int factorial(int);
main(){
	int num;
	printf("Please input a number: ");
	scanf("%d", &num);
	printf("Factorial(%d)=%d\n", num, factorial(num));
}

int factorial(int n)
{
	int k, total = 1;
	for (k = 1; k <= n ; k++)
		total *= k;
	return total;
}

/* ex6-6a.c */
void increase();
main(){
	/* 測試auto儲存類別的生命週期 */
	int count;
	printf("Testing storage class << auto >>\n");
	/* 使用for迴圈呼叫increase() */
	for (count = 1; count <= 5; count++){
		printf("# %d call: ", count);
		increase();
	}
	printf("Testing end!!\n");
}

/* 定義increase()，ai儲存類別為auto，輸出累加的結果 */
void increase(){
	auto int ai = 100;  /* 定義ai為auto儲存類別，初值為100 */
	printf("ai = %d\n", ++ai);
}

/* ex6-6b.c */
void increase();
main(){
	/* 測試static儲存類別的生命週期 */
	int count;
	printf("Testing storage class << static >>\n");
	/* 使用for迴圈呼叫increase() */
	for (count = 1; count <= 5; count++){
		printf("#%d call: ", count);
		increase();
	}
	printf("Testing end!!\n");
}

/* 定義increase()，si儲存類別為static，輸出累加的結果 */
void increase()
{
	static int si = 100; /* 定義si為static儲存類別，初值為100 */
	printf("si = %d\n", ++si);
}

/* ex6-6c.c */
main(){
	/* 測試register儲存類別 */
	int count1, count2;
	register long num = 0;  /* 定義num為register儲存類別 */
	printf("Testing storage class << register >>\n");
	/* 巢狀迴圈對num作累加的動作 */
	printf("Number: \n");
	for (count1 = 1; count1 <= 500; count1++)
		for (count2 = 1; count2 <= 500; count2++)
			printf("\r%d", ++num);
	printf("\nTesting end!!\n");
}

/* ex6-6d-1.c */
/* one file of Project*/
int sum();
int i=100, j=200;
main(){
	int total;
	total=sum();
	printf("total=%d\n", total);
}

/* ex6-6d-2.c */
/* other file of project */
/* 定義sum()*/

int sum(){
	extern int i, j;
	return (i+j);
}

/* ex7-2a.c*/
main(){
	/* 輸入10個整數存入陣列，再從陣列讀出 */
	int num[10], i;
	for (i = 0; i < 10; i++){
		printf("請輸入num[%d]的資料: ", i);
		scanf("%d", &num[i]);
	}
	printf("\n此陣列有下列元素:\n");
	for (i = 0; i < 10; i++)
		printf("num[%d]=%d\n", i, num[i]);
}

/* ex7-2b.c*/
main(){
	/* 輸出陣列每一元素的位址 */
	int num[10], i;
	for (i = 0; i < 10; i++){
		printf("&num[%d]=%p, num+%d=%p\n", i, &num[i], i, num+i);
	}
}

/* ex7-2c.c*/
main(){
	/* 設定陣列初值 */
	double num1[6] = {11.1, 22.2, 33.3, 44.4, 55.5};
	int num2[ ] = {1, 2, 3, 4, 5, 6};  /* 元素個數隨初值個數而定 */
	int i;

	for (i = 0; i < 6; i++)
		printf("num1[%d]=%.1f\n", i, num1[i]);

	printf("\n\n");
	for (i = 0;  i < 6; i++)
		printf("num2[%d]=%d\n",i, num2[i]);

	printf("\nnum1陣列佔 %d bytes\n", sizeof(num1));
	printf("num2陣列佔 %d bytes\n", sizeof(num2));
}

/* ex7-3a.c*/
main(){
	int num[2][5];
	int index1, index2;

	for (index1 = 0; index1 < 2; index1++)
		for (index2 = 0; index2 < 5; index2++)
			printf("&num[%d][%d]: %p\n", index1, index2, &num[index1][index2]);

	printf("\n");
	printf("num=%p, num[0]=%p\n", num, num[0]);
	printf("num+1=%p, num[0]+1=%p\n", num+1, num[0]+1);
}

/* ex7-3b.c */
main(){
	/* 於二維陣列中，再將輸入值由二維陣列中取出並印出 */
	int num[2][3];
	int index1, index2;
	/* 以巢狀迴圈處理二維陣列輸入 */
	for (index1 = 0; index1 < 2; index1++)
		for (index2 = 0; index2 < 3; index2++){
			printf("請輸入num[%d][%d]的資料: ", index1, index2);
			scanf("%d", &num[index1][index2]);
		}
	printf("\n此二維陣列的資料如下:\n");
	for (index1 = 0; index1 < 2; index1++){
		for (index2 = 0; index2 < 3; index2++)
			printf("%3d ", num[index1][index2]);
		printf("\n");
	}
}

/* ex7-3c.c*/
main(){
	/* 此二維陣列表示-考三天(列註標)，一天考三科(行註標) */
	int score[3][3] = { {74, 72, 63}, {83, 92, 74}, {84, 82, 65} };
	int index1, index2, total = 0;
	for (index1 = 0; index1 < 3; index1++) /* 外圈控制考試日期 */{
		printf("\n第 %d 天的分數分別為: ", index1+1);
		for (index2 = 0; index2 < 3; index2++) /* 內圈控制考試科目 */{
			printf("%3d", score[index1][index2]);  /* 印出各科成績 */
			total += score[index1][index2];  /* 將成績加總 */
		}
	}
	printf("\n\n總分: %d\n", total);
	printf("平均分數: %.2f\n", total / 9.0);
}

/* ex7-3d.c*/
main(){
	int score[2][3] = {10, 20, 30, 40, 50};
	int i, j;
	for (i = 0; i < 2; i++)
		for (j = 0; j < 3; j++)
			printf("score[%d][%d] = %d\n", i, j, score[i][j]);
}

/* ex7-3e.c*/
main(){
	int score[2][3] = {{10, 20}, {30, 40, 50}};
	int i, j;
	for (i = 0; i < 2; i++)
		for (j = 0; j < 3; j++)
			printf("score[%d][%d] = %d\n", i, j, score[i][j]);
}

/* ex7-4a.c*/
main(){
	int i, j, k, temp, size;
	int arr[]={80, 30, 40, 70, 50, 60};
	size = sizeof(arr) / sizeof(int);
	printf(".....Before sorting........\n");
	for (i=0; i<=size-1; i++)
		printf("%d ", arr[i]);
	printf("\n");
	for (i=1; i<=25; i++)
		printf("-");
	printf("\n");

	/**********Bubble sort****************/
	for (i=0; i<size-1; i++) {
		for (j=0; j<size-i-1; j++)
			if (arr[j] > arr[j+1]) {
				temp = arr[j];
				arr[j] = arr[j+1];
				arr[j+1] = temp;
			}
		printf("#%d pass: ", i+1);
		for (k=0; k<size; k++)
			printf("%d ", arr[k]);
		printf("\n");
	}
	/************************************/
	for (i=1; i<=25; i++)
		printf("-");
	printf("\n");
	printf(".....After sorting.......\n");
	for (i=0; i<size; i++)
		printf("%d ", arr[i]);
	printf("\n");
}

/* ex7-4b.c*/
main(){
	int i, j, k, temp, flag, size;
	int arr[]={80, 30, 40, 70, 50, 60};
	size = sizeof(arr) / sizeof(int);
	printf(".....Before sorting........\n");
	for (i=0; i<=size-1; i++)
		printf("%d ", arr[i]);
	printf("\n");
	for (i=1; i<=25; i++)
		printf("-");
	printf("\n");

	/**********Bubble sort****************/
	for (i=0; i<size-1; i++) {
		flag=0;
		for (j=0; j<size-i-1; j++)
			if (arr[j] > arr[j+1]) {
				flag=1;  /* 若有對調，則將flag設為1 */
				temp = arr[j];
				arr[j] = arr[j+1];
				arr[j+1] = temp;
			}
		printf("#%d pass: ", i+1);
		for (k=0; k<size; k++)
			printf("%d ", arr[k]);
		printf("\n");
		if (flag == 0) break;	/* 沒有對調，表示已完成排序 */
	}
	/************************************/
	for (i=1; i<=25; i++)
		printf("-");
	printf("\n");
	printf(".....After sorting.......\n");
	for (i=0; i<size; i++)
		printf("%d ", arr[i]);
	printf("\n");
}

/* ex7-4c.c*/
main(){
	int i, j, k, temp, flag, size;
	int arr[]={80, 90, 40, 70, 50, 60};
	size = sizeof(arr) / sizeof(int);
	printf(".....Before sorting.......\n");
	for (i=0; i<=size-1; i++)
		printf("%d ", arr[i]);
	printf("\n");
	for (i=1; i<=25; i++)
		printf("-");
	printf("\n");

	/**********Bubble sort****************/
	/* 總共有size個資料，所以會有size-1次的pass */
	for (i=0; i<size-1; i++) {
		flag=0; /* 用來判斷是否要再繼續排序 */
		/* 印出第幾次的 pass 的資料 */
		printf("#%2d pass 的資料計有: ", i+1);
		for (k=0; k<size-i; k++)
			printf("%d ", arr[k]);
		printf("\n");

		/* 要比較的資料，第一次pass會減1，第二次pass會減2，第三次pass會減3，依此類推*/
		/* 所以迴圈的條件運算式為 j<size-1-i */
		for (j=0; j<size-1-i; j++){
			/* 當此筆資料大於下一筆資料時，則加以對調 */
			if (arr[j] > arr[j+1]) {
				flag=1;  /* 若有對調，則將flag設為1 */
				temp = arr[j];
				arr[j] = arr[j+1];
				arr[j+1] = temp;
			}
			/* 印出每一次compare後的資料 */
			printf("   #%d compare: ", j+1);
			for (k=0; k<size-i; k++)
				printf("%d ", arr[k]);
			printf("\n");
		}

		/* 印出每一次pass後的資料 */
		printf("#%d pass 結束時資料順序如下: \n", i+1);
		for (k=0; k<size; k++)
			printf("%d ", arr[k]);
		printf("\n\n");
		if (flag == 0) break;	/* 沒有對調，表示已完成排序 */
	}
	/************************************/
	for (i=1; i<=25; i++) printf("-");
	printf("\n");
	printf(".....After sorting.......\n");
	for (i=0; i<size; i++)
		printf("%d ", arr[i]);
	printf("\n");
}

/* ex7-4d.c */
main(){
	int i, j, temp, flag, size;
	int left, right, mid, kd, bingo;
	int arr[]={80, 90, 40, 70, 50, 60};
	size = sizeof(arr) / sizeof(int);

	/**********Bubble sort*************/
	for (i=0; i<size-1; i++) {
		flag=0;
		for (j=0; j<size-i-1; j++)
			if (arr[j] > arr[j+1]) {
				flag=1;
				temp = arr[j];
				arr[j] = arr[j+1];
				arr[j+1] = temp;
			}
		if (flag == 0)
			break;
	}
	for (i=0; i<=size-1; i++)
		printf("%d ", arr[i]);
	printf("\n\n");
	/***********Binary search***********/
	printf("您要尋找那一個數字(輸入是英文字母將結束): ");
	while (scanf("%d", &kd) == 1) {
		left=0;
		right=size-1;
		bingo = 0;
		while (left <= right) {
			mid = (left+right)/2;
			if (kd == arr[mid]) {
				bingo=1;
				break;
			}
			if (kd < arr[mid])
				right = mid-1;
			else
				left = mid+1;
		}
		if (bingo == 1)
			printf("在 arr[%d] 找到 %d.\n", mid, kd);
		else
			printf("對不起，查無此資料! \n");
		printf("\n您要尋找那一個數字(輸入是英文字母將結束): ");
	}
}

/* ex8-1a.c */
main(){
	/* 定義一指向int資料型態的指標，並觀察其內容 */
	int num = 100;
	int *ptr;    /* ptr是一個指向int的指標 */
	ptr = &num;  /* ptr指向num的位址 */

	/* 印出num的位址及內容 */
	printf("num 在記憶體的位址為 %p\n", &num);
	printf("num 變數值為 %d\n", num);

	/* 印出ptr變數位址 */
	printf("&ptr is %p\n", &ptr);

	/* 印出ptr所指向的位址 */
	printf("ptr is %p\n", ptr);

	/* 印出ptr所指向位址的內容  */
	printf("*ptr =  %d\n", *ptr);
}

/* ex8-1b.c */
main(){
	int num = 100, *ptr;
	ptr = &num; /* 指定num的記憶體位址給ptr */
	printf("開始時的變數值如下:\n");
	printf("num=%d, *ptr=%d\n\n", num, *ptr);

	num = 200;  /* num的值改為200 */
	printf("透過 num= 200 更改num變數值\n");
	printf("num=%d, *ptr=%d\n\n", num, *ptr);

	*ptr=300;
	printf("也可透過 *ptr=300 更改num變數值\n");
	printf("num=%d, *ptr=%d\n", num, *ptr);
}

/* ex8-1c.c */
main(){
	/* 要求輸入半徑以計算圓面積 */
	double pi = 3.14, radius, area;
	double *ptr = &pi;  /* 設定ptr初值為&pi */

	printf("請輸入圓的半徑: ");
	scanf("%lf", &radius);
	area = radius * radius * pi;
	printf("圓的面積為 %.2f\n", area, pi);

	*ptr = 3.14159;  /* 藉由*ptr更改pi的值 */
	area = radius * radius * pi;
	printf("經由*ptr更改pi為3.14159後，面積為%.3f\n", area);
}

/* ex8-1d.c */
main(){
	/* 測試一指標變數所佔記憶體空間，並與基本型態變數比較 */
	printf("char 佔 %d bytes\n", sizeof(char));
	printf("int 佔 %d bytes\n", sizeof(int));
	printf("float 佔 %d bytes\n", sizeof(float));
	printf("double 佔 %d bytes\n\n", sizeof(double));

	printf("char * 佔 %d bytes\n", sizeof(char *));
	printf("int * 佔 %d bytes\n", sizeof(int *));
	printf("float * 佔 %d bytes\n", sizeof(float *));
	printf("double * 佔 %d bytes\n", sizeof(double *));
}

/* ex8-2a.c */
main(){
	int array[10] = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100};
	int i;
	int *ptr = array;  /* 將ptr指向array */

	for (i = 0; i < 10; i++)
		printf("array[%d]=%3d\n", i, array[i]);
	printf("\n");

	for (i = 0; i < 10; i++){
		printf("*(ptr+%d)=%d\n", i, *(ptr+i));
	}
	system("PAUSE");;
}

/* ex8-2b.c */
main(){
	char string[10] = "computer";  /* 給定字元陣列（字串）初值 */
	char *ptr = string; /* 將string第一個元素的位址指定給ptr指標 */
	printf("陣列string的內容是 %s\n", string);

	/* 以下皆輸出陣列第一個元素的記憶體位址 */
	printf("ptr: %p\n", ptr);
	printf("string: %p\n", string);
	printf("&string[0]: %p\n\n", &string[0]);

	/* 以下皆輸出陣列第二個元素的記憶體位址 */
	printf("ptr+1: %p\n", ptr+1);
	printf("string+1: %p\n", string+1);
	printf("&string[1]: %p\n\n", &string[1]);

	/* 以下輸出陣列的內容 */
	printf("*ptr: %c, string[0]: %c\n", *ptr, string[0]);
	printf("*(ptr+1): %c, string[1]: %c\n", *(ptr+1), string[1]);
	printf("*ptr+1: %c, string[0]+1: %c\n", *ptr+1, string[0]+1);
}

/* ex8-2c.c */
main(){
	int num[10] = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100};
	int *ptr = num;
	printf("&num[0]=%p, num=%p\n", &num[0], num);
	printf("ptr: %p\n", ptr);
	printf("*ptr: %d\n\n", *ptr);

	++ptr;
	printf("ptr=%p\n", ptr);
	printf("*ptr: %d\n", *ptr);
	printf("*(ptr-1): %d\n", *(ptr-1));
	printf("*(ptr+1): %d\n", *(ptr+1));
}

/* ex8-2d.c */
main(){
	int num[10] = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100};
	printf("num: %p\n", num);
	printf("*num: %d\n", *num);
	printf("num+1: %u\n", num++); /* 遞增num，發生錯誤 */
	printf("*num: %d", *num);
}

/* ex8-2e.c */
main(){
	/* 修改範例 7-2d, 使其可以執行 */
	int num[10] = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100};
	printf("num: %p\n", num);
	printf("*num: %d\n", *num);
	printf("num+1: %p\n", num+1);
	printf("*num: %d\n", *num);
}

/* ex8-3a.c */
void change(int, int);  /* 函數change()的原型宣告 */
main(){
	int x, y;
	printf("請輸入 x: ");
	scanf("%d", &x);
	printf("請輸入 y: ");
	scanf("%d", &y);
	/* 呼叫change函數，將x、y傳遞給change()函數 */
	change(x, y);
	printf("\n呼叫對調的函數後!!\n");
	/* 執行完change函數後，印出x及y */
	printf("x 是 %d\n", x);
	printf("y 是 %d\n", y);
}

/* 定義change函數，參數為a、b */
/* 交換a及b的值 */
void change(int a, int b)
{
	int temp;
	temp = a;
	a = b;
	b = temp;
}

/* ex8-3b.c */
void change(int *, int *);
main(){
	int x, y;
	printf("請輸入 x: ");
	scanf("%d", &x);
	printf("請輸入 y: ");
	scanf("%d", &y);
	/* 呼叫change函數 */
	/* 傳遞x及y的位址給swap()函數 */
	change(&x, &y);
	/* 執行完change函數後，印出x及y */
	printf("\n對調之後!!\n");
	printf("x 是 %d\n", x);
	printf("y 是 %d\n", y);
}

/* 定義change函數，參數為*a、*b */
/* 交換*a及*b的值 */
void change(int *a, int *b)
{
	int temp;
	temp = *a;
	*a = *b;
	*b = temp;
}

/* ex8-4a.c */
int sum(int *, int);
/* 計算陣列所有元素的和 */
main(){
	int arr[] = {10, 20, 30, 40, 50, 60};
	int total, n, i;

	/* 計算arr陣列中有多少元素*/
	n=sizeof(arr)/sizeof(arr[0]);
	total = sum(arr, n);
	for (i=0; i<n; i++)
		printf("arr[%d]=%d\n", i, arr[i]);
	printf("\n");
	printf("陣列的總和 : %d\n", total);
}

int sum(int *p, int num)
{
	int i , total=0;
	for (i =0; i < num; i++)
		total += *(p+i);
	return total;
}

/* ex8-4b.c */
/* 計算二維陣列的每一列和每一行的總和 */
#define ROWS 4
#define COLS 3
void sum_rows(int arr[][COLS], int);
void sum_cols(int arr[][COLS], int);
main(){
	int array[ROWS][COLS] = {{1, 3, 5},{2, 4, 6},{7, 9, 11},{8, 10, 12}};
	sum_rows(array, ROWS);
	sum_cols(array, COLS);
}

void sum_rows(int arr[][COLS], int rows)
{
	int r, c, total;
	for (r = 0; r < rows; r++){
		total = 0;
		for (c = 0; c < COLS; c++)
			total += arr[r][c];
		printf("row %d : sum = %d\n", r, total);
	}
	printf("\n");
}

void sum_cols(int arr[][COLS], int rows)
{
	int r, c, total;
	for (c = 0; c< COLS; c++){
		total = 0;
		for (r = 0; r < rows; r++)
			total += arr[r][c];
		printf("col %d : sum = %d\n", c, total);
	}
}

/* ex9-1a.c */
main(){
	/* 定義一指標變數 onePointer，指向int變數number；
		定義一雙重指標變數twoPointer，指向指標變數onePointer */
	int **twoPointer, *onePointer, number;
	/* 設定number、onePointer及twoPointer */
	number = 100;
	onePointer = &number;
	twoPointer = &onePointer;

	/* 印出number的位址及值 */
	printf("&number: %p \n", &number);
	printf("number: %d\n\n", number);

	/* 印出onePointer的位址及其相關資訊*/
	printf("&onePointer: %p \n", &onePointer);
	printf("onePointer: %p \n", onePointer);
	printf("*onePointer: %d\n\n", *onePointer);

	/* 印出twoPointer的位址及其相關資訊*/
	printf("&twoPointer: %p \n", &twoPointer);
	printf("twoPointer: %p \n", twoPointer);
	printf("*twoPointer: %p \n", *twoPointer);
	printf("**twoPointer: %d\n\n", **twoPointer);

	/* 印出單一與雙重指標佔多少bytes */
	printf("onePointer佔 %d bytes\n", sizeof(onePointer));
	printf("twoPointer佔 %d bytes\n", sizeof(twoPointer));
}

/* ex9-2a.c */
main(){
	int i;
	char str[4][20] = {"Department", "of", "Information", "Management"};
	for (i = 0; i<4; i++){
		printf("str + %d = %p\n", i, str+i);
		printf("*(str + %d) = %p\n", i, *(str+i));
		printf("str [%d] = %p\n\n", i, str[i]);
	}
}

/* ex9-2b.c */
main(){
	char *str[4] = {"Department", "of", "Information", "Management"};
	printf("*str=%p\n", *str);
	printf("**str=%c\n", **str);
	printf("*(str+2)=%p\n", *(str+2));
	printf("**(str+2)=%c\n", **(str+2));
	printf("*str+2)=%p\n", *str+2);
	printf("**(str+2)=%c\n", *(*str+2));
}

/* ex9-2c.c */
main(){
	int arr[2][3] = {{10, 20, 30}, {40, 50, 60}};
	int *ptr[2]={arr[0], arr[1]};
	printf("*ptr=%p\n", *ptr);
	printf("**ptr=%d\n", **ptr);
	printf("*(ptr+1)=%p\n", *(ptr+1));
	printf("**(ptr+1)=%d\n", **(ptr+1));

	printf("*ptr+2=%p\n", *ptr+2);
	printf("*(*ptr+2)=%d\n", *(*ptr+2));
	printf("*(ptr+1)+2=%p\n", *(ptr+1)+2);
	printf("*(*(ptr+1)+2)=%d\n", *(*(ptr+1)+2));
}

/* ex9-2d.c */
main(){
	int a[] = {0, 1, 2, 3, 4};
	int *p[] = {a, a+1, a+2, a+3, a+4};
	int **pp = p;
	printf("**pp = %d\n", **pp);
	printf("*(*(pp+2)+2) = %d\n", *(*(pp+2)+2));
}

/* ex10-1a.c */
main(){
	/* 測試scanf函數在輸入字元的缺點 */
	char ch;
	int i;
	for (i = 1; i <=3 ; i++){
		printf("#%d 的輸入資料為: ", i);
		scanf("%c", &ch);
		printf("#%d 的輸出資料為: %c\n\n", i, ch);
	}
}

/* ex10-1b.c */
main(){
	/* 處理 scanf()輸入字元的缺點 */
	char ch;
	int i;
	for (i = 1; i <=3 ; i++) /* 使用迴圈要求輸入3次字元 */{
		printf("#%d 的輸入資料為: ", i);
		scanf("%c", &ch);  /* 以scanf()輸入字元 */
		printf("#%d 的輸出資料為: %c\n\n", i, ch);
		while (getchar() != '\n')
			continue;
	}
}

/* ex10-1c.c */
void output(char);  /* 函數output()的原型宣告 */
main(){
	/* 測試字元的輸出入函數 */
	char ch;
	printf("\n\n...使用getch()輸入...\n");
	printf("請輸入一字元: ");
	ch = getch();
	output(ch);
	printf("\n\n...使用getche()輸入...\n");
	printf("請輸入一字元: ");
	ch = getche();
	output(ch);
	printf("\n\n...使用getchar()輸入...\n");
	printf("請輸入一字元: ");
	ch = getchar();
	output(ch);
	printf("\n");
}

/* 定義output()函數，傳遞參數以c接收 */
void output(char c)
{
	printf("\n使用putchar()輸出字元: ");
	putchar(c);
}

/* ex10-1d.c */
main(){
	/* 選擇輸出使用getche() */
	char option;
	do{
		printf("\n");
		printf("1) iPod nano\n");
		printf("2) iPhone \n");
		printf("3) iMac\n");
		printf("請選擇您要的商品(1..3) 或 q 結束: ");
		option = getche();  /* 使用getche()來接收選項 */
		switch (option) /* switch敘述 */{
		case '1':
			printf("\n您選擇的商品是 iPod nano\n");
			break;
		case '2':
			printf("\n您選擇的商品是 iPhone\n");
			break;
		case '3':
			printf("\n您選擇的商品是 iMac\n");
			break;
		case 'q':
			exit(0);
		default:
			printf("\n沒有這樣商品，請重新輸入 !!!\n");
		}
	} while (option != 'q');
}

/* ex10-2a.c */
main(){
	char ch;
	printf("請輸入一個字元: ");
	ch = getche();
	if (isalnum(ch))
		printf("\n%c 是一英文字母或數字\n", ch);
	else
		printf("\n%c 不是一字元為英文字母或數字\n", ch);
}

/* ex10-2b.c */
main(){
	char ch;
	printf("請輸入一個字元: ");
	ch = getche();
	if (isalpha(ch))
		printf("\n%c 為英文字母\n", ch);
	else if (isdigit(ch))
		printf("\n%c 為數字\n", ch);
	else
		printf("\n%c 不是一英文字母或數字\n", ch);
}

/* ex10-2c.c */
main(){
	char ch;
	printf("請輸入一個字元: ");
	ch = getche();
	if (isupper(ch))
		printf("\n%c 是大寫英文字母 \n", ch);
	else if (islower(ch))
		printf("\n%c 是小寫英文字母\n", ch);
	else
		printf("\n%c 不是英文字母\n", ch);
}

/* ex10-2d.c */
main(){
	char ch;
	printf("請輸入一個英文字母: ");
	ch = getche();
	/* 執行toupper */
	printf("\n此字母的大寫是 %c\n", toupper(ch));
	/* 執行tolower */
	printf("此字母的小寫是 %c\n", tolower(ch));
}

/* ex10-3a.c */
main(){
	/* 字串輸出入，使用printf()及scanf() */
	char str[10];
	printf("Please enter a string: ");
	scanf("%s", str);
	printf("The string is: %s\n", str);
}

/* ex10-3b.c */
main(){
	char name[20], ans;
	int score;

	printf("請輸入您的大名: ");
	/* 使用 gets()來取得字串 */
	gets(name);
	do{
		printf("\n請輸入您的分數: ");
		scanf("%d", &score);
		printf("確定嗎 (y/n)? ");
		ans = getche();  /* 使用getche()取得使用者的回答 */
	} while (ans != 'y');

	/* 使用puts()輸出字串 */
	puts("\n\n=======================");
	printf("    Name: ");
	puts(name);
	printf("    Score: %d\n", score);
	puts("=======================");
}

/* ex10-3c.c */
main(){
	/* 使用字元陣列方式設定初值 */
	char str[10] = {'A', 'p', 'p', 'l', 'e', '\0'};
	printf("設定的字串是: ");
	puts(str);
}

/* ex10-3d.c */
main(){
	char str[] = "Apple";
	char *str2 = "iPod nano";
	printf("設定的字串是: \n");
	puts(str);
	puts(str2);
}

/* ex10-3e.c */
main(){
	/* 宣告字串陣列，並設定初值 */
	char str[2][20] = {"Microsoft", "Windows Vista"};
	int index;
	for (index = 0; index < 2; index++)
		printf("字串 %d 為 %s\n", index+1, str[index]);
}

/* ex10-3f.c */
main(){
	/* 以另一種方式印出 */
	char str[3][20] = {"iPod", "iMac", "iPhone"};
	int index;
	for (index = 0; index < 3; index++)
		printf("字串 %d 為 %s\n", index+1, str+index);
}

/* ex10-3g.c */
void output(char []);
main(){
	char str1[] = "Good", str2[] = " idea\n";
	/* 以字串為參數，呼叫函數output() */
	output(str1);
	output(str2);
}

void output(char str[])
{
	printf("%s", str);
}

/* ex10-3h.c */
char *message(int);  /* 函數原型宣告 */
main(){
	char *info;
	int input;
	printf("Enter a number: ");
	scanf("%d", &input);
	/* 呼叫message()函數，以info接回傳回值 */
	info = message(input);
	puts(info);
}

/* 根據參數num大於、小於或等於0傳回不同的訊息 */
char *message(int num)
{
	if (num > 0)
		return "Number is positive";
	else if (num < 0)
		return "Number is negative";
	else
		return "Number is zero";
}

/* ex10-3i.c */
char *input();  /* 函數原型宣告 */
main(){
	/* 錯誤的示範 */
	char *str;
	str = input();  /* 呼叫input()函數，string接收函數傳回值 */
	printf("Input string is %s\n", str);
}

char *input()
{
	char strin[20];
	printf("Enter a string: ");
	gets(strin);
	return strin;
}

/* ex10-4a.c */
main(){
	/* 要求輸入一個字串，並計算字串長度 */
	char string[30];
	int length;
	printf("請輸入一字串: ");
	gets(string);
	length = strlen(string);
	printf(" %s字串的長度為: %d\n", string, length);
}

/* ex10-4b.c */
main(){
	/* 要求輸入一字串，並將小寫英文字母轉為大寫 */
	char string[30];
	printf("輸入全為小寫的字串: ");
	gets(string);
	strupr(string);
	printf("將小寫轉為大寫: %s\n", string);
}

/* ex10-4c.c */
main(){
	/* 要求輸入一字串，將字串中英文大寫字母轉為小寫 */
	char string[30];
	printf("輸入全為大寫的字串: ");
	gets(string);
	strlwr(string);
	printf("將大寫轉為小寫: %s\n", string);
}

/* ex10-4d.c */
main(){
	/* 要求輸入一字串，並將字串拷貝到另一字串 */
	char string1[30], string2[30];
	printf("請輸入第一個字串: ");
	gets(string1);
	printf("執行拷貝的動作...\n");
	strcpy(string2, string1);  /* 呼叫strcpy()函數 */
	printf("第二個字串為: %s\n", string2);
}

/* ex10-4e.c */
main(){
	/* 要求輸入字串，拷貝字串前 N 個字元到另一字串 */
	char string1[30], string2[30]={'\0'};
	int size;
	printf("請輸入第一個字串: ");
	gets(string1);
	printf("請問要拷貝多少個字元: ");
	scanf("%d", &size);
	printf("執行拷貝的動作...\n\n");
	strncpy(string2, string1, size);
	printf("第二個字串為: %s\n", string2);
}

/* ex10-4f.c */
main(){
	/* 要求輸入兩個字串，將第一個字串附加到第二個字串後 */
	char string1[30], string2[30];
	printf("請輸入第一個字串: ");
	gets(string1);  /* 輸入第一個字串 */
	printf("請輸入第二個字串: ");
	gets(string2);  /* 輸入第二個字串 */
	printf("執行附加的動作...\n");
	strcat(string2, string1);  /* 呼叫strcat()函數 */
	printf("第一個字串為: %s\n", string1);
	printf("第二個字串為: %s\n", string2);
}

/* ex10-4g.c */
main(){
	/* 要求輸入字串，將一字串的前N個字元，附加到另一個字串 */
	char string1[30], string2[30];
	int size;
	printf("請輸入第一個字串: ");
	gets(string1);
	printf("請輸入第二個字串: ");
	gets(string2);
	printf("請問要附加多少個字元: ");
	scanf("%d", &size);  /* 輸入附加字元數 */
	printf("執行附加的動作...\n\n");
	strncat(string2, string1, size);  /* 呼叫strncat()函數 */
	printf("第一個字串為: %s\n", string1);
	printf("第二個字串為: %s\n", string2);
}

/* ex10-4h.c */
main(){
	/* 兩字串的比較 */
	char string1[30], string2[30];
	int difference;
	printf("請輸入第一個字串: ");
	gets(string1);
	printf("請輸入第二個字串: ");
	gets(string2);
	printf("執行比較的動作...\n");
	difference = strcmp(string1, string2);
	switch (difference){
	case 0:
		printf("%s 與 %s 是相同的\n", string1, string2);
		break;
	case 1:
		printf("%s 大於 %s\n", string1, string2);
		break;
	case -1:
		printf("%s 小於 %s\n", string1, string2);
		break;
	}
}

/* ex10-4i.c */
main(){
	/* 兩字串的比較 */
	char string1[30], string2[30];
	int difference;
	printf("請輸入第一個字串: ");
	gets(string1);
	printf("請輸入第二個字串: ");
	gets(string2);
	printf("執行stricmp比較的動作...\n\n");
	difference = stricmp(string1, string2);
	switch (difference){
	case 0:
		printf("%s 與 %s 是相同的\n", string1, string2);
		break;
	case 1:
		printf("%s 大於 %s\n", string1, string2);
		break;
	case -1:
		printf("%s 小於 %s\n", string1, string2);
		break;
	}
}

/* ex10-4j.c */
main(){
	/* 兩字串的比較 */
	char string1[30], string2[30];
	int difference, size;
	printf("請輸入第一個字串: ");
	gets(string1);
	printf("請輸入第二個字串: ");
	gets(string2);
	printf("請輸入要比較的字元數: ");
	scanf("%d", &size);

	printf("執行strncmp比較的動作...\n\n");
	difference = strncmp(string1, string2, size);
	switch (difference){
	case 0:
		printf("%s 與 %s 是相同的\n", string1, string2);
		break;
	case 1:
		printf("%s 大於 %s\n", string1, string2);
		break;
	case -1:
		printf("%s 小於 %s\n", string1, string2);
		break;
	}
}

/* ex10-4j.c */
main(){
	/* 兩字串的比較 */
	char string1[30], string2[30];
	int difference, size;
	printf("請輸入第一個字串: ");
	gets(string1);
	printf("請輸入第二個字串: ");
	gets(string2);
	printf("請輸入要比較的字元數: ");
	scanf("%d", &size);

	printf("執行strnicmp比較的動作...\n\n");
	difference = strnicmp(string1, string2, size);
	switch (difference){
	case 0:
		printf("%s 與 %s 是相同的\n", string1, string2);
		break;
	case 1:
		printf("%s 大於 %s\n", string1, string2);
		break;
	case -1:
		printf("%s 小於 %s\n", string1, string2);
		break;
	}
}

/* ex10-4L.c */
main(){
	char string[30], ch, *ptr;
	printf("請輸入一字串: ");
	gets(string);
	printf("請輸入欲搜尋的字元: ");
	ch = getche();
	printf("搜尋中...\n\n");
	ptr = strchr(string, ch);
	printf("字串的第一個字元的位址是: %x\n", string);
	printf("字元%c在字串%s的位址是: %x\n", ch, string, ptr);
}

/* ex10-4m.c */
main(){
	char string[30], ch, *ptr;
	printf("請輸入一字串: ");
	gets(string);
	printf("請輸入欲搜尋的字元: ");
	ch = getche();
	printf("搜尋中...\n\n");
	ptr = strrchr(string, ch);
	printf("字串的第一個字元的位址是: %x\n", string);
	printf("字元%c在字串%s的位址是: %x\n", ch, string, ptr);
}

/* ex11-1a.c */
main(){
	/* 宣告學生成績的結構型態 */
	struct student{
		char name[20];      	/* 學生姓名 */
		int score; 	            /* 學生成績*/
	}  rec1;                   /* 定義結構變數rec1 */
	struct student rec2;        /* 定義結構變數rec2 */

	/* 以sizeof()計算結構變數rec1與rec2所佔記憶體空間 */
	printf("rec1 結構佔 %d bytes\n", sizeof(rec1));
	printf("rec2 結構佔 %d bytes\n", sizeof(rec2));
}

/* ex11-1b.c */
main(){
	/* 宣告結構triangle的型態，以成員運算子" . "存取結構結構成員*/
	struct triangle{
		int length, height;	/* 三角形的長與高 */
		double area;	    /* 三角形的面積 */
	};
	struct triangle tri;

	printf("請輸入三角形的長: ");
	scanf("%d", &tri.length);  /* 以tri.length存取結構成員length */

	printf("請輸入三角形的高: ");
	scanf("%d", &tri.height);  /* 以tri.height存取結構成員height */

	tri.area = tri.length * tri.height / 2.0;  /* 以tri.area存取結構成員area */
	printf("三角形的面積為: %.2f\n", tri.area);
}

/* ex11-1c.c */
main(){
	struct order{
		char product[20];	/* 產品名稱 */
		double price;  	    /* 產品單價 */
		int quantity;	    /* 產品數量 */
	};

	struct order num1 = {"iPod nano", 6700.0, 20}; /* 以設定方式給予初值 */
	struct order num2;
	double total;
	total =num1.price * num1.quantity;

	printf("請輸入產品名稱: ");
	scanf("%s", num2.product);
	printf("請輸入產品價格: ");
	scanf("%lf", &num2.price);
	printf("請輸入訂購數量: ");
	scanf("%d", &num2.quantity);

	/* total產品總價為產品單價乘以產品數量 */
	total =num2.price * num2.quantity;
	printf("\n<< 定單列表 >>\n");
	printf("產品名稱: %s\n", num1.product);
	printf("價格: %.1f\n", num1.price);
	printf("數量: %d\n", num1.quantity);
	printf("總共價格: %.1f\n\n", total);

	printf("產品名稱: %s\n", num2.product);
	printf("價格: %.1f\n", num2.price);
	printf("數量: %d\n", num2.quantity);
	printf("總共價格: %.1f\n", total);
}

/* ex11-2a.c */
main(){
	struct employee{
		char id[7];	    /* ID號碼 */
		char name[20];	/* 員工姓名 */
		int salary;	    /* 所得薪資 */
	};

	/* 宣告結構變數，並設定其初值 */
	struct employee general = {"D62128", "Johnson", 39000};

	/* 定義結構指標變數，指向結構變數general的位址 */
	struct employee *ptr = &general;

	/* 使用->運算子取得各結構元素 */
	printf("<< 使用->運算子取得各結構元素>>\n");
	printf("ID number: %s\n", ptr->id);
	printf("Employee Name: %s\n", ptr->name);
	printf("Salary: %d\n\n", ptr->salary);

	/* 使用(*).運算子取得各結構元素 */
	printf("<< 使用(*).運算子取得各結構元素 >>\n");
	printf("ID number: %s\n", (*ptr).id);
	printf("Employee Name: %s\n", (*ptr).name);
	printf("Salary: %d\n", (*ptr).salary);
}

/* ex11-2b.c */

struct work
{
	char name[20];   /* 姓名 */
	int hours;	     /* 工作時數 */
	int pay;	     /* 時薪 */
	int total_pay;	 /* 總工資 */
};
void calculate(struct work *);
main(){
	struct work service;  /* 定義結構變數 */
	service.pay = 120;
	printf("請輸入您的姓名: ");
	gets(service.name);
	printf("請輸入工作時數: ");
	scanf("%d", &service.hours);
	calculate(&service);  /* 呼叫calculate()函數，傳送service結構位址 */
	printf("您總共的薪資是 $%d\n", service.total_pay);
}

/* 定義calculate()函數，以結構指標變數接收結構位址 */
void calculate(struct work *ptr)
{
	ptr->total_pay = ptr->hours * ptr->pay;  /* 計算總工資 */
}

/* ex11-3a.c */
main(){
	/* 利用結構陣列存取資料 */
	struct student{
		int id;
		char name[10];
		double score;
	};
	/* 定義結構陣列，設定其初值 */
	struct student classes[5] = {
		{10811, "John", 88.0},
		{10812, "Mary", 82.0},
		{10813, "Bob", 76.5},
		{10814, "Helen", 91.0},
		{10815, "Peter", 61.5}
	};
	int index;
	printf("   學生名單如下 \n");
	printf("   ------------\n\n");
	printf("學號   姓名        分數\n");
	/* 使用for迴圈將資料印出 */
	for (index = 0; index < 5; index++)
		printf("%d  %-10s %5.1f\n", classes[index].id,
			   classes[index].name, classes[index].score);
}

/* ex11-3b.c */
struct student
{
	int id;
	char name[10];
	double score;
};
struct student classes[10];
int index=0;

void create();  /* create()函數的原型定義 */
void list();    /* list()函數的原型定義 */
main(){

	char option;
	do{
		printf("\n1 => create student data\n");
		printf("2 => list student data\n");
		printf("3 => quit\n");
		printf("Please enter your choice: ");
		option = getche();  /* 輸入選項 */
		puts("");  /* 跳行 */
		switch (option){
			/* 選項1呼叫create()函數做新增工作 */
		case '1':
			create();
			break;

			/* 選項2呼叫list()函數做列印工作 */
		case '2':
			list();

			break;
		case '3':
			printf("Bye bye!!\n");

			break;
		default :
			printf("Option error!!\n");
		}
	}  while (option != '3'); /* 選擇為3則跳出迴圈 */
}

/* 	定義 create()函數 */
void create(){
	if (index >= 10) {
		printf("The array is full\n");
		return;
	}

	printf("\n<< Creating student data >>\n");
	printf("Student ID: ");
	scanf("%d", &classes[index].id);
	while (getchar()!='\n')
		continue;

	printf("Student name: ");
	scanf("%s", classes[index].name);

	printf("Student score: ");
	scanf("%lf", &classes[index].score);
	index++;
}

/* 	定義list()函數 */
void list(){
	int i;
	printf("\n<< Listing student data >>\n");
	/* 利用for迴圈將結構陣列中的資料一一列出 */
	for (i = 0; i < index; i++)
		printf("%-10d  %-10s %5.1f\n", classes[i].id, classes[i].name, classes[i].score);
}

/* ex11-4a.c */
main(){
	/* 宣告結構型態 */
	struct student{
		char name[20];
		int score;
	};
	struct student *ptr;  /* 定義結構指標ptr */

	/* 使用malloc()函數配置記憶體 */
	ptr = (struct student *) malloc(sizeof(struct student));

	printf("請輸入學生的姓名: ");
	gets(ptr->name);
	printf("請輸入學生的成績: ");
	scanf("%d", &ptr->score);
	printf("\n學生的姓名是 %s\n", ptr->name);
	printf("成績為 %d\n", ptr->score);
}

/* ex11-4b.c */
main(){
	/* 宣告結構型態 */
	struct node{
		char name[20];
		int  score;
		struct node *next;
	};
	struct node *ptr1, *ptr2, *ptr3, *current;

	/* 使用malloc函數配置記憶體 */
	ptr1 = (struct node *) malloc(sizeof(struct node));
	printf("請輸入ptr1節點的姓名: ");
	scanf("%s", ptr1->name);
	printf("請輸入ptr1節點的分數: ");
	scanf("%d", &ptr1->score);

	ptr2 = (struct node *) malloc(sizeof(struct node));
	printf("\n請輸入ptr2節點的姓名: ");
	scanf("%s", ptr2->name);
	printf("請輸入ptr2節點的分數: ");
	scanf("%d", &ptr2->score);
	ptr1->next = ptr2; /* 將 ptr1 的 next 指標指向 ptr2 */

	ptr3 = (struct node *) malloc(sizeof(struct node));
	printf("\n請輸入ptr3節點的姓名: ");
	scanf("%s", ptr3->name);
	printf("請輸入ptr3節點的分數: ");
	scanf("%d", &ptr3->score);
	ptr3->next = NULL;   /* ptr3 的 next 指標設為NULL */
	ptr2->next = ptr3;   /* 將 ptr2 的 next 指標指向 ptr3 */

	current = ptr1;
	printf("\n\n縺結串列的資料如下:\n");
	while (current != NULL){
		printf("%10s ", current->name);
		printf("%5d\n", current->score);
		current = current->next;
	}
}

/* ex11-4c.c */
void insert();
void list();

struct student
{
	int id;	               /* ID號碼 */
	char name[10];	       /* 學生姓名 */
	double score;	       /* 學生分數 */
	struct student *next;  /* 指向下一個鏈結 */
};

/* 定義結構指標，head指向第一個鏈結 */
struct student *head, *ptr;
main(){
	char option;
	head = (struct student *) malloc(sizeof(struct student));
	head -> next = NULL;    /* head指向的節點不存任何資料 */

	do{
		/* 使用選項讓使用者選擇新增、列印或結束 */
		printf("\n1 => 新增一節點\n");
		printf("2 => 列印串列的所有節點\n");
		printf("3 => 結束\n");
		printf("請選擇一項目: ");
		option = getche();  /* 輸入選項 */
		puts("");            /* 跳行 */
		switch (option){
		case '1':
			insert();
			break;
		case '2':
			list();
			break;
		case '3':
			printf("Bye bye!!");
			break;
		default :
			printf("Option error!!\n");
		}
	}  while (option != '3'); /* 選擇為3則跳出迴圈 */
}

/* 定義insert()，此函數不接受任何參數，且不傳回任何值 */
/* 新增一筆資料於鏈結串列的前端 */
void insert(){
	/* 以malloc()函數配置記憶體 */
	ptr = (struct student *) malloc(sizeof(struct student));

	printf("\n<< Creating student data >>\n");
	printf("Student ID <int> : ");
	scanf("%d", &ptr->id);

	printf("Student name <string> : ");
	scanf("%s", ptr->name);

	printf("Student score <double> : ");
	scanf("%lf", &ptr->score);

	/* 加入前端的步驟 */
	ptr->next = head->next;
	head->next = ptr;
}

/* 定義list()，此函數不接受任何參數，且不傳回任何值 */
/* 列印資料於螢幕 */
void list(){
	struct student *current;
	if (head->next == NULL)
		printf("The linked list is empty\n");
	else{
		current = head->next;		/* 將node指向head */
		printf("\n<< Listing student data >>\n");

		while (current != NULL)	/* 列印資料直到current為空指標 */{
			printf("%-10d %-10s %-10.2f\n", current->id, current->name, current->score);
			current = current->next;
		}
	}
}

/* ex11-4d.c */
void insert();
void del();
void list();

struct student
{
	int id;	               /* ID號碼 */
	char name[10];	       /* 學生姓名 */
	double score;	       /* 學生分數 */
	struct student *next;  /* 指向下一個鏈結 */
};

/* 定義結構指標，head指向第一個鏈結 */
struct student *head, *ptr;
main(){
	char option;
	head = (struct student *) malloc(sizeof(struct student));
	head -> next = NULL;    /* head指向的節點不存任何資料 */
	do{
		/* 使用選項讓使用者選擇新增、刪除、列印或結束 */
		printf("\n1 => 新增一節點\n");
		printf("2 => 刪除一節點\n");
		printf("3 => 列印串列的所有節點\n");
		printf("4 => 結束\n");
		printf("請選擇一項目: ");
		option = getche();  /* 輸入選項 */
		puts("");            /* 跳行 */
		switch (option){
		case '1':
			insert();
			break;
		case '2':
			del();
			break;
		case '3':
			list();
			break;
		case '4':
			printf("Bye bye!!\n");
			break;
		default :
			printf("Option error!!\n");
		}
	}  while (option != '4'); /* 選擇為3則跳出迴圈 */
}

/* 定義insert()，此函數不接受任何參數，且不傳回任何值 */
/* 新增一筆資料於鏈結串列的前端 */
void insert(){
	/* 以malloc()函數配置記憶體 */
	ptr = (struct student *) malloc(sizeof(struct student));

	printf("\n<< Insert a student data >>\n");
	printf("Student ID <int> : ");
	scanf("%d", &ptr->id);

	printf("Student name <string> : ");
	scanf("%s", ptr->name);

	printf("Student score <double> : ");
	scanf("%lf", &ptr->score);

	ptr->next = head->next;
	head->next = ptr;
}

/* 定義del()，此函數不接受任何參數，且不傳回任何值 */
/* 刪除鏈結串列前端資料 */
void del(){
	struct student *current;
	current = head->next ;

	/* 判斷鏈結串列是不是空的 */
	if (current == NULL)
		printf("The linked list is empty !!!\n");
	else{
		head->next = current->next;  /*利用這一敘述將前端的節點除 */
		printf("\n<< Delete a student data >>\n");
		printf("%-10d %-10s %-10.2f\n",
				current->id, current->name, current->score);
		free(current);
	}
}

/* 定義list()，此函數不接受任何參數，且不傳回任何值 */
/* 列印資料於螢幕 */
void list(){
	struct student *current;
	if (head->next == NULL)
		printf("No data\n");
	else{
		current = head->next;	/* 將node指向head */
		printf("\n<< Listing student data >>\n");

		while (current != NULL){	/* 列印資料直到current為空指標 */
			printf("%-10d %-10s %-10.2f\n",
					current->id, current->name, current->score);
			current = current->next;
		}
	}
}

/* ex12-2-1a.c */
main(){
	/* 開啟一檔案，將其內容輸出至螢幕 */
	FILE *fptr;  /* 宣告檔案結構指標 */
	char ch;

	/* 步驟一: 開啟檔案為讀取型態 */
	fptr = fopen("c:\\cfile.dat", "w");

	/* 步驟二: 呼叫檔案字元輸出函數fputc() */
	printf("請輸入一行字元:\n");
	while ((ch = getchar()) != '\n')
		fputc(ch, fptr);

	/* 步驟三: 關閉檔案 */
	fclose(fptr);
}

/* ex12-2-1b.c */
main(){
	/* 開啟一檔案，將其內容輸出至螢幕 */
	FILE *fptr;  /* 宣告檔案結構指標 */
	char input;

	/* 開啟檔案為讀取型態 */
	if ((fptr = fopen("c:\\cfile.dat", "r")) == NULL) {
		puts("cfile.dat檔案無法開啟!");
		exit(1);
	}

	/* 呼叫檔案字元輸入函數fgetc() */
	while ((input = fgetc(fptr)) != EOF)
		putchar(input);

	fclose(fptr);	/* 關閉檔案 */
}

/* ex12-2-2a.c */
main(){
	/* 將使用者輸入之文章寫入至檔案 */
	FILE *fptr;

	/* input[81]表示一行最多可輸入80個字元（不包含空字元） */
	char input[81], filename[20];
	printf("請輸入欲寫入的檔名: ");
	gets(filename);
	fptr = fopen(filename, "w");	/* 開啟檔案 */

	puts("請輸入字串，當字串為 quit 表示結束:\n");
	/* 以行為單位，利用gets()輸入字串 */

	while (strcmp(gets(input), "quit") != 0){
		fputs(input, fptr); /* 利用fputs()將字串輸出至檔案 */
		fputc('\n', fptr);  /* 輸出跳行字元至檔案中 */
	}
	fclose(fptr);
}

/* ex12-2-2b.c */
main(){
	/* 使用fgets()讀取檔案中的字串後輸出 */
	FILE *fptr;
	char str[81], filename[20];
	printf("請輸入欲讀取的檔名: ");
	gets(filename);
	if ((fptr = fopen(filename, "r")) == NULL)	/* 開啟檔案 */{
		printf("%s 無法開啟!!!\n", filename);
			exit(1);
	}

	while (fgets(str, 81, fptr) != NULL)	/*使用fgets()讀取字串*/
		printf("%s", str);	/* 輸出字串 */
	fclose(fptr);		/* 關閉檔案 */
}

/* ex12-2-3a.c */
main(){
	/* 將使用者輸入的資料儲存至檔案中 */
	FILE *fptr;
	char no[10], filename[20], answer;
	int score_c, score_j;
	printf("請輸入欲寫入的檔名: ");
	gets(filename);	/* 鍵入輸出檔名 */
	fptr = fopen(filename, "w");  /* 開啟檔案 */
	do{	/* 輸入各項資料 */
		printf("輸入學號: ");
		scanf("%s", no);
		printf("輸入 C 語言的成績: ");
		scanf("%d", &score_c);
		printf("輸入 JAVA 語言的成績:");
		scanf("%d", &score_j);
		/* 利用fprintf()將資料寫入指定的檔案中 */
		fprintf(fptr, "%s %d %d\n", no, score_c, score_j);
		/* 詢問是否輸入下一筆 */
		do{
			printf("繼續輸入否 (Y/N)? ");
			answer = getche();
			printf("\n\n");
		} while (toupper(answer) != 'Y' && toupper(answer) != 'N');
	} while (toupper(answer) == 'Y');
	fclose(fptr);
}

/* ex12-2-3b.c */
main(){
	/* 計算、輸出學生成績 */
	FILE *fptr;
	char no[10], filename[20];
	int score_c, score_j, total_c = 0, total_j = 0, ctr = 0;
	double avg_c, avg_j;
	printf("請輸入讀取的檔名: ");
	gets(filename);
	if ((fptr = fopen(filename, "r")) == NULL) /* 開啟檔案 */{
		printf("%s 無法開啟!!!", filename);
		exit(1);
	}
	puts("==================");
	puts("ID      C  JAVA");
	puts("==================");

	/* 使用fscanf()讀取檔案資料，EOF判斷檔案是否結束 */
	while (fscanf(fptr, "%s %d %d", no, &score_c, &score_j) != EOF){
		printf("%-6s %3d %3d\n", no, score_c, score_j);
		total_c += score_c;
		total_j += score_j;
		ctr++;
	}
	puts("==================");
	/* 計算平均值，使用(double)轉型使計算結果為double型態 */
	avg_c = (double) total_c / ctr;
	avg_j = (double) total_j / ctr;
	printf("C 語言的平均分數是: %.1f\n", avg_c);
	printf("JAVA 語言的平均分數是: %.1f\n", avg_j);
	fclose(fptr);
}

/* ex12-2-4a.c */
main(){
	FILE *fptr;
	/* 利用fwrite()將結構陣列寫入檔案 */
	struct test {
		char name[10];
		int c_score;
	};
	/* 定義結構陣列 */
	struct test student[3] = { {"Bright", 97}, {"Linda", 96}, {"Jennifer ", 92} };

	/* 以二進位模式開啟檔案 */
	fptr = fopen("c:\\dfile2.dat", "w");
	/* 將結構資料寫入檔案，一次寫入三筆 */
	fwrite(student, sizeof(struct test), 3, fptr);
	printf("資料已被寫入到 C:\dfile2.dat\n");
	fclose(fptr);	/* 關閉檔案 */
}

/* ex12-2-4b.c */
main(){
	/* 利用fread()讀取檔案中的結構陣列 */
	struct test {  /* 宣告test結構型態 */
		char name[10];
		int c_score;
	};
	struct test student[3];  /* 定義test結構陣列 */
	FILE *fptr;
	int i;
	if ((fptr = fopen("c:\\dfile2.dat", "r")) == NULL) /* 開啟檔案 */{
		puts("dfile2.dat無法開啟!!!");
		exit(1);
	}
	fread(student, sizeof(struct test), 3, fptr);  /* 從檔案中讀取資料 */
	printf("學生的分數如下:\n");
	printf("----------------\n");
	for (i = 0; i < 3; i++) /* 輸出讀取結果 */
		printf("%-10s %5d\n", student[i].name, student[i].c_score);
	fclose(fptr);
}

/* ex12-3-1a.c */
main(){
	/* 開啟一檔案，將其內容輸出至螢幕 */
	FILE *fptr;  /* 宣告檔案結構指標 */
	char ch;

	/* 開啟檔案為讀取型態 */
	if ((fptr = fopen("c:\\cfile.dat", "w")) == NULL) {
		puts("File open failed!");
		exit(1);
	}

	/* 呼叫檔案字元輸出函數fputc() */
	while ((ch = getchar()) != '\n')
		fputc(ch, fptr);

	fclose(fptr);	/* 關閉檔案 */
}

/* ex12-3-1b.c */
main(){
	/* 開啟一檔案，將其內容輸出至螢幕 */
	FILE *fptr;  /* 宣告檔案結構指標 */
	char input;

	/* 開啟檔案為讀取型態 */
	if ((fptr = fopen("c:\\cfile.dat", "r")) == NULL) {
		puts("File open failed!");
		exit(1);
	}

	/* 呼叫檔案字元輸入函數fgetc() */
	while ((input = fgetc(fptr)) != EOF)
		putchar(input);

	fclose(fptr);
}

/* ex12-3-1c.c */
main(){	/* 將使用者輸入之文章輸出至檔案中 */
	FILE *fptr;  /* 定義檔案結構指標 */
	/* input[81]表示一行最多可輸入80個字元（不包含空字元） */
	char input[81], filename[20];
	int i;
	printf("Enter ");
	gets(filename);
	fptr = fopen(filename, "w");  /* 開啟檔案為寫入型態 */
	puts("Enter an article(enter \"<finish>\" to exit):");
	/* 以行為單位，利用gets()函數來達到使用者輸入的目的 */
	/* 當輸入<finish>則結束輸入 */
	while (strcmp(gets(input), "<finish>") != 0)
		for (i = 0; i < 80; i++)
		{	/* 當輸入為空字元，則將'\n'寫入檔案 */
			if (input[i] == '\0'){
				fputc('\n', fptr);  /* 將'\n'寫入檔案 */
				break;
			}
			fputc(input[i], fptr);  /* 將input[i]寫入檔案 */
		}
	fclose(fptr);
}

/* ex12-3-3b.c */
main(){	/* 計算、輸出學生成績 */
	FILE *fptr;
	char no[10], filename[20];
	int score_c, score_j, total_c = 0, total_j = 0, ctr = 0;
	double avg_c, avg_j;
	printf("Enter input filename: ");
	gets(filename);
	if ((fptr = fopen(filename, "r")) == NULL) /* 開啟檔案 */{
		puts("File open failed!");
		exit(1);
	}
	puts("==================");
	puts("ID      C  JAVA");
	puts("==================");

	/* 使用fscanf()函數讀取檔案資料，EOF判斷檔案是否結束 */
	while (fscanf(fptr, "%s %d %d", no, &score_c, &score_j) != EOF){
		printf("%-6s %3d %3d\n", no, score_c, score_j);
		total_c += score_c;
		total_j += score_j;
		ctr++;
	}
	puts("==================");
	/* 計算平均值，使用(float)轉型使計算結果為double型態 */
	avg_c = (double) total_c / ctr;
	avg_j = (double) total_j / ctr;
	printf("Average C   : %.1f\n", avg_c);
	printf("Average JAVA: %.1f\n", avg_j);
	fclose(fptr);
}

/* ex12-3-3b.c */
main(){
	/* 將使用者輸入的資料儲存至檔案中 */
	FILE *fptr;
	char no[10], filename[20], answer;
	int score_c, score_j;
	printf("Enter output filename: ");
	gets(filename);  /* 鍵入輸出檔名 */
	fptr = fopen(filename, "w");  /* 開啟檔案 */
	do{	/* 輸入各項資料 */
		printf("Enter Student NO: ");
		scanf("%s", no);
		printf("Enter C language score: ");
		scanf("%d", &score_c);
		printf("Enter JAVA language score: ");
		scanf("%d", &score_j);
		/* 利用fprintf()將資料寫入指定的檔案中 */
		fprintf(fptr, "%s %d %d\n", no, score_c, score_j);
		/* 詢問是否輸入下一筆 */
		do{
			printf("Enter next (Y/N)? ");
			answer = getche();
			printf("\n");
		} while (toupper(answer) != 'Y' && toupper(answer) != 'N');
	} while (toupper(answer) == 'Y');
	fclose(fptr);
}

/* ex12-3-4a.c */
main(){
	/* 利用fwrite()函數將結構陣列寫入檔案 */
	struct test {
		char name[10];
		int c_score;
	};
	/* 定義結構陣列 */
	struct test student[3] = { {"Bright", 97}, {"Linda", 96}, {"Jennifer", 92}};
	FILE *fptr;
	fptr = fopen("c:\\dfile2.dat", "wb");           /* 以二進位模式開啟檔案 */
	fwrite(student, sizeof(struct test), 3, fptr);  /* 將結構寫入檔案 */
	printf("資料已被寫入到 C:\dfile2.dat\n");
	fclose(fptr);
	getch();
}

/* ex12-3-4b.c */
main(){
	/* 利用fread()函數讀取檔案中的結構陣列 */
	struct test {	/* 宣告test結構型態 */
		char name[10];
		int c_score;
	};
	struct test student[3];  /* 定義test結構陣列 */
	FILE *fptr;
	int i;
	if ((fptr = fopen("c:\\dfile2.dat", "rb")) == NULL) /* 開啟檔案 */{
		puts("File open failed!");
		exit(1);
	}
	fread(student, sizeof(struct test), 3, fptr);  /* 從檔案中讀取資料 */
	for (i = 0; i < 3; i++) /* 輸出讀取結果 */
		printf("%-10s %5d\n", student[i].name, student[i].c_score);
	fclose(fptr);
	getch();
}

/* ex12-3-4c.c */
main(){	/* 利用fread()函數讀取檔案中的結構陣列 */
	struct test {  /* 宣告test結構型態 */
		int var1;
		char var2;
		double var3;
		char var4[10];
	};
	struct test strus[2];  /* 定義test結構陣列 */
	FILE *fptr;
	int i;
	if ((fptr = fopen("c:\\dfile2.dat", "rb")) == NULL) /* 開啟檔案 */{
		puts("File open failed!");
		exit(1);
	}
	fread(strus, sizeof(struct test), 2, fptr);  /* 從檔案中讀取資料 */
	for (i = 0; i < 2; i++) /* 輸出讀取結果 */
		printf("%d %c %.2f %s\n", strus[i].var1,strus[i].var2,
			strus[i].var3, strus[i].var4);
	fclose(fptr);	/* 關閉檔案 */
}

/* ex12-3-4d.c */
main(){	/* 載入舊檔，要求輸入新的資料後儲存檔案 */
	/* 宣告student結構型態 */
	struct student {
		char no[10];
		char name[20];
		int score_c;
		int score_j;
	};
	struct student data[30];  /* 定義結構陣列 */
	FILE *fptr;
	char filename[20], answer = 'Y';
	int i, ctr = 0;
	/* 鍵入輸入檔名，若為skip表示放棄載入檔案 */
	printf("Enter input filename(enter \"skip\" to ignore): ");
	gets(filename);
	/* 當檔名不是skip，以二進位模式開啟輸入檔 */
	if (stricmp(filename, "skip") != 0){
		if ((fptr = fopen(filename, "rb")) == NULL){
			puts("File open failed!");
			exit(1);
		}
		/* 以fread()讀取檔案資料，ctr會接收讀取筆數 */
		ctr = fread(data, sizeof(struct student), 30, fptr);
		printf("%s file has %d data\n", filename, ctr);
		for (i = 0; i< ctr; i++)
			printf("%s %s %d %d\n", data[i].no, data[i].name,
				   data[i].score_c, data[i].score_j);
		fclose(fptr);  /* 關閉輸入檔 */
	}

	do{
		if (ctr >= 30) /* 當資料筆數≧30，將不再要求輸入資料 */{
			puts("Data space full!");
			break;
		}
		/* 輸入結構中各元素值 */
		printf("Enter student NO: ");
		scanf("%s", data[ctr].no);
		printf("Enter student name: ");
		scanf("%s", data[ctr].name);
		printf("Enter C language score: ");
		scanf("%d", &data[ctr].score_c);
		printf("Enter JAVA language score: ");
		scanf("%d", &data[ctr].score_j);
		ctr++;
		/* 詢問是否輸入下一筆 */
		do{
			printf("Enter next (Y/N)? ");
			answer = getche();
			printf("\n");
		} while ((answer = toupper(answer)) != 'Y' && answer != 'N');
	} while (answer == 'Y');
	/* 鍵入輸出檔名 */
	printf("Enter output filename: ");
	scanf("%s", filename);
	/* 以二進位模式開啟輸出檔 */
	fptr = fopen(filename, "wb");
	/* 使用fwrite()將資料寫入檔案 */
	fwrite(data, sizeof(struct student), ctr, fptr);
	fclose(fptr);  /* 關閉輸出檔 */
}

/* ex12-3-5a.c */
main(){
	/* 隨機讀取檔案中的記錄 */
	/* 定義student結構 */
	struct test {
		char name[10];
		int c_score;
	};
	struct test student;
	FILE *fptr;
	int record, count=0;
	long offset;

	if ((fptr = fopen("c:\\dfile2.dat", "rb")) == NULL) /* 開啟檔案 */{
		puts("File open failed!");
		exit(1);
	}
	printf("Size of struct test is %d\n", sizeof(struct test));
	while (fread(&student, sizeof(struct test), 1, fptr) == 1)
		count++;
	printf("c:\\dfile2.dat has %d record(s)\n", count);
	for ( ; ; ) /* 無窮迴圈 */{
		printf("\nEnter record number to list (enter 0 to exit): ");
		scanf("%d", &record);  /* 輸入查看哪一筆資料 */
		if (record == 0)       /* 輸入為0會跳出迴圈 */
			break;
		offset = (record - 1) * sizeof(struct test);  /* 計算offset */
		if (fseek(fptr, offset, 0) != 0 || record > count) /* 位移檔案指標 */{
			puts("Data not found!");
			continue;
		}
		fread(&student, sizeof(struct test), 1, fptr);  /* 讀取資料 */
		/* 輸出資料 */
		printf("Student naem: %s\n", student.name);
		printf("C language score: %d\n", student.c_score);
	}
	fclose(fptr);
	getch();
}

/* ex12-3-6a.c */
main(){
	/* 測試fprintf()是否發生錯誤 */
	FILE *fptr;
	int num[5], i;
	if ((fptr = fopen("test.dat", "w")) == NULL) /* 開啟檔案 */{
		puts("File open failed!");
		exit(1);
	}
	for (i = 0; i < 5; i++){
		printf("Enter a number: ");
		scanf("%d", &num[i]);
		fprintf(fptr, "%d\n", num[i]);
		if (ferror(fptr)) /* 若寫入動作發生錯誤，執行perror() */{
			perror("Write error");  /* 印出系統錯誤訊息 */
			fclose(fptr);
					exit(2);
		}
	}
	fclose(fptr);
}

/* ex12-3a.c  */
main(){
	FILE *fptr;
	char ch;
	int ctr = 0;
	if ((fptr = fopen("c:\\temp\\text.dat", "r")) == NULL)  {
		puts("File c:\\temp\\text.dat not found!");
		exit(1);
	}
	while ((ch=fgetc(fptr))!= EOF){
		printf("%c", ch);
		ctr++;
	}
	printf("以文字檔格式讀取上述資料，共有 %d bytes\n", ctr);
	fclose(fptr);
}

/* ex12-3b.c */
main(){
	FILE *fptr;
	int ctr = 0;
	char ch;
	if ((fptr = fopen("c:\\temp\\text.dat", "rb")) == NULL)  {
		puts("File c:\\temp\\text.dat not found!");
		exit(1);
	}
	while ((ch=fgetc(fptr))!= EOF){
		printf("%c", ch);
		ctr++;
	}
	printf("以二進位讀取上述資料，共有 %d bytes\n", ctr);
	fclose(fptr);
}

/* ex12-3c.c  */
main(){
	FILE *fptr;
	int narr[] = {6, 16, 26, 36, 46, 56};
	int n, i;
	fptr = fopen("c:\\temp\\bin.dat", "w");
	fwrite(narr, sizeof(narr), 1, fptr);
	fclose(fptr);
	if ((fptr = fopen("c:\\temp\\bin.dat", "r")) == NULL)  {
		puts("File c:\\temp\\bin.dat not found!");
		exit(1);
	}
	while (fread(&n, sizeof(int), 1, fptr) == 1)
		printf("%d ", n);
	fclose(fptr);
}

/* ex12-3d.c */
main(){
	FILE *fptr;
	int narr[] = {6, 16, 26, 36, 46, 56};
	int n, i;
	fptr = fopen("c:\\temp\\bin.dat", "w");
	fwrite(narr, sizeof(narr), 1, fptr);
	fclose(fptr);
	if ((fptr = fopen("c:\\temp\\bin.dat", "rb")) == NULL){
		puts("File c:\\temp\\bin.dat not found!");
		exit(1);
	}
	while (fread(&n, sizeof(int), 1, fptr) == 1)
		printf("%d ", n);
	fclose(fptr);
}

/* ex12-4a.c */
#include <fcntl.h>
#define BUFFSIZE 512  /* 定義BUFFSIZE大小 */
main(){
	char buffer[BUFFSIZE], filename[20];
	int handle, ctr;
	printf("Enter input filename: ");
	gets(filename);
	if ((handle = open(filename, O_RDONLY)) == -1) /* 開啟檔案 */{
		puts("File open failed!");
		exit(1);
	}
	/* 利用fread()讀取檔案資料 */
	if ((ctr = read(handle, buffer, BUFFSIZE)) == -1){
		perror("Read error");
		exit(2);
	}
	write(1, buffer, ctr);  /* 利用write()將資料輸出至螢幕 */
	close(handle);
}

/* ex12-4a.c */
main(){
	/* 隨機讀取檔案中的記錄 */
	/* 定義student結構 */
	struct test{
		char name[10];
		int c_score;
	};
	struct test student;
	FILE *fptr;
	int record, count=0;
	long offset;

	if ((fptr = fopen("c:\\dfile2.dat", "rb")) == NULL) /* 開啟檔案 */{
		puts("dfile2.dat無法開啟!!!");
		exit(1);
	}

	while (fread(&student, sizeof(struct test), 1, fptr) == 1)
		count++;
	printf("c:\\dfile2.dat 共有 %d 筆資料\n", count);
	for ( ; ; ) /* 無窮迴圈 */{
		printf("請問您要找尋那一筆資料(0 表示結束): ");
		scanf("%d", &record);	/* 輸入查看哪一筆資料 */
		if (record == 0)		/* 輸入為0會跳出迴圈 */
			break;
		offset = (record - 1) * sizeof(struct test);	/* 計算offset */
		if (fseek(fptr, offset, 0) != 0 || record > count)	/* 位移檔案指標 */{
			puts("無此筆資料!");
			continue;
		}
		fread(&student, sizeof(struct test), 1, fptr);	/* 讀取資料 */
		/* 輸出資料 */
		printf("\n");
		printf("姓名: %s\n", student.name);
		printf("C 語言分數: %d\n", student.c_score);
	}
	fclose(fptr);
}

/* ex13-1-2a.c */
main(){
	/* 輸入5個整數，並將其輸出 */
	int array[5], i;
	for (i = 0; i < 5; i++){
		printf("請輸入第 %d 個元素的資料: ", i+1);
		scanf("%d", &array[i]);
	}
	printf("\n此陣列計有下列資料: \n");
	for (i = 0; i < 5; i++)
		printf("array[%d]=%d\n", i, array[i]);
}

/* ex13-1-2b.c */
#define MAX 5  /* 使用#define定義陣列元素為5個 */
main(){
	/* 更改範例13-1-2a */
	/* 輸入5個整數，並將其輸出 */
	int array[MAX], i;
	for (i = 0; i < MAX; i++){
		printf("請輸入第 %d 個元素的資料: ", i+1);
		scanf("%d", &array[i]);
	}
	printf("\n此陣列計有下列資料: \n");
	for (i = 0; i < MAX; i++)
		printf("array[%d]=%d\n", i, array[i]);
}

/* ex13-1-2c.c */
#define SQUARE1(n) n*n      /* 定義SQUARE1(n) */
#define SQUARE2(n) (n)*(n)   /* 定義SQUARE2(n) */

int square(int);    /* 定義一函數 */
main(){
	int sqrt;
	sqrt = SQUARE1(6+2);
	printf("SQUARE1(6+2)=%d\n", sqrt);

	sqrt = SQUARE2(6+2);
	printf("SQUARE2(6+2)=%d\n", sqrt);

	sqrt = square(6+2);
	printf("square(6+2)=%d\n", sqrt);
}

int square(n){
	return n*n;
}

/* ex13-1-3a.c */
#define RATE 32.68
#ifndef RATE 32.78
#define RATE 32.78
#endif
main(){
	double usDollar, ntDollar;
	printf("請輸入您有多少美金? ");
	scanf("%lf", &usDollar);

	ntDollar=usDollar*RATE;
	printf("您可換 %.2f 的台幣。\n", ntDollar);
}

/* ex13-2-1a.c */
main(){
	char string[10];
	int result;
	printf("請輸入一整數的字串: ");
	gets(string);
	result = atoi(string);
	printf("將字串轉換為整數: %d\n", result);
}

/* ex13-2-1b.c */
main(){
	char string[10];
	double result;
	printf("請輸入一浮點數的字串: ");
	gets(string);
	result = atof(string);  /* 呼叫atof() */
	printf("將字串轉換為浮點數: %.2f\n", result);
}

/* ex13-2-1c.c */
main(){
	/* 使用strtol()函數將字串某一基底數，轉換為長整數 */
	char string[20], *endptr;
	long int final;
	int base;
	printf("請輸入一字串: ");
	scanf("%s", string);
	printf("基底數是多少? ");
	scanf("%d", &base);
	final = strtol(string, &endptr, base);
	printf("轉換後的結果為: %ld\n", final);
	printf("endptr指向: %s\n", endptr);
}

/* ex13-2-2a.c */
main(){
	/* 利用abs()取得絕對值 */
	int value, result;
	printf("請輸入一負的整數: ");
	scanf("%d", &value);
	result = abs(value);  /* 呼叫abs() */
	printf("|%d| = %d\n", value, result);
}

/* ex13-2-2b.c */
main(){
	/* 利用exp()計算指數值 */
	double value, result;
	printf("請輸入一浮點數: ");
	scanf("%lf", &value);
	result = exp(value);  /* 呼叫exp() */
	printf("exp(%.2f) = %.2g\n", value, result);
}

/* ex13-2-2c.c */
main(){
	/* 利用sqrt()計算平方根 */
	double value, result;
	printf("請輸入一數值: ");
	scanf("%lf", &value);
	result = sqrt(value);  /* 呼叫sqrt() */
	printf("此數的平方根為: %.5f\n", result);
}

/* ex13-2-2d.c */
main(){
	/* 利用pow()取得某數的n次方值 */
	double value, n, result;
	printf("請輸入一數值: ");
	scanf("%lf", &value);
	printf("多少次方: ");
	scanf("%lf", &n);

	result = pow(value, n);
	printf("%.1f 的%.1f次方為: %.2f\n", value, n, result);
}

/* ex13-2-2e.c */
#define MAX 10
main(){
	/* 利用rand()函數來產生亂數 */
	int i;
	puts("<<產生的亂數如下:>>");
	for (i = 0; i < MAX; i++)
		printf("%d\n", rand());  /* 呼叫rand() */
}

/* ex13-2-2f.c */
#define MAX 10
#define random(num) (rand() % (num))
main(){
	/* 利用random()巨集來產生亂數 */
	int i, range;
	printf("最大的亂數值為: ");
	scanf("%d", &range);
	puts("<<產生的亂數如下>>");
	for (i = 0; i < MAX; i++)
		printf("%d\n", random(range) +1);
}

/* ex13-2-2g.c */
#define MAX 10
main(){
	int i, seed;
	printf("請給一新的數值當種子: ");
	scanf("%d", &seed);
	srand(seed);  /* 呼叫seed，重新設定亂數種子 */
	puts("<<產生的亂數如下>>");
	for (i = 0; i < MAX; i++)
		printf("%d\n", rand());  /* 呼叫rand，印出亂數 */
}

/* ex13-2-2h.c */
#define MAX 10
#define random(num) (rand() % (num))
#define randomize() srand((unsigned) time(NULL))
main(){
	int i, range;
	printf("最大的亂數值為: ");
	scanf("%d", &range);  /* 輸入亂數範圍 */
	puts("<<產生的亂數如下>>");
	randomize();  /* 以randomize()設定亂數種子 */
	for (i = 0; i < MAX; i++)
		printf("%d\n", random(range)+1);
}

/* ex13-2-3a.c */
main(){
	struct tm *ptrnow;
	time_t loc_now, std_now;
	time(&loc_now);
	time(&std_now);
	ptrnow = localtime(&loc_now);  /* 呼叫localtime() */
	printf("區域時間: %s", asctime(ptrnow));
	ptrnow = gmtime(&std_now);  /* 呼叫gmtime() */
	printf("標準時間: %s", asctime(ptrnow));
}

/* ex13-2-4a.c */
main(){
	system("dir/w");
}
main(){
	struct node{
		char *name;
		int score;
		struct node *next;
	};

	struct node *p, *q, *r, *head, *current;
	p=(struct node *) malloc(sizeof(struct node));
	p->name = "Peter";
	p->score = 90;
	q=(struct node *) malloc(sizeof(struct node));
	q->name = "Nancy";
	q->score = 92;
	r=(struct node *) malloc(sizeof(struct node));
	r->name = "Mary";
	r->score = 94;

	p->next = q;
	q->next = r;
	r->next = NULL;

	head = p;
	current = head;
	while (current != NULL){
		printf("%s %d\n", current->name, current->score);
		current = current->next;
	}
}