1
#include <stdio.h>
int main()
{
int n;
char ch;
n = 0;
while ((ch = getchar()) != EOF)
{
n++;
}
printf("字符数: %d\n", n);
system("pause");
return 0;
}
2
#include <stdio.h>
int main()
{
char ch;
int i;
i = 0;
while ((ch = getchar()) != EOF)
{
if (ch < ' ')
{
if (ch == '\t')
{
i++;
printf("\\t:%4d ", ch + 64);
}
else if (ch == '\n')
{
i++;
printf("\\n:%4d ", ch + 64);
}
}
else
{
if (i % 10 == 0 && i != 0)
printf("\n");
i++;
printf("%2c:%4d ", ch, ch);
}
}
system("pause");
return 0;
}
3
#include <stdio.h>
#include <ctype.h>
int main()
{
char ch;
int i, j;
i = 0;
j = 0;
while ((ch = getchar()) != EOF)
{
if (islower(ch))
i++;
else if (isupper(ch))
j++;
}
printf("小写字母: %d个 \t大写字母: %d个\n", i, j);
system("pause");
return 0;
}
4
#include <stdio.h>
#include <ctype.h>
#include <stdbool.h>
int main()
{
char ch;
int i, j;
bool word;
word = false;
i = 0;
j = 0;
while ((ch = getchar()) != EOF)
{
if (isalpha(ch))
{
word = true;
i++;
}
else if (isspace(ch))
word = false;
if (!word)
j++;
}
printf("单词个数: %d, 平均每个单词的字母数: %d\n", j, i / j);
system("pause");
return 0;
}
5
a 原版
//一个拖沓且错误的猜数字程序
#include <stdio.h>
int main()
{
int guess = 50;
int min = 0;
int max = 101;
char ch;
char responst;
printf("选择一个从1到100的整数。我会尝试猜测它。\n");
printf("如果我的猜测是正确的，那么回应一个 y，如果它是错误的，则回答 n。\n");
printf("呃...你的号码是 %d?\n", guess);
while ((responst = getchar()) != 'y') //获取响应，与Y做对比
{
while (getchar() != '\n')
continue;
if (responst == 'n')
{
bk:printf("我猜大了还是猜小了: \n");
printf("a.大了 \tb.小了\n");
scanf_s("%c", &ch);
while (getchar() != '\n')
continue;
if (ch == 'a')
{
max = guess;
guess -= (max - min) / 2;
printf("恩，然后，它是 %d?\n", guess);
}
else if (ch == 'b')
{
min = guess;
guess += (max - min) / 2;
printf("恩，然后，它是 %d?\n", guess);
}
else
{
printf("对不起，我只懂a或b。\n");
goto bk;
}
}
else
printf("对不起，我只懂y或n。\n");
}
printf("我知道我可以做到！\n");
system("pause");
return 0;
}
b 使用指针版本
//一个拖沓且错误的猜数字程序
#include <stdio.h>
void guess_a(int *guess, int *min, int *max);
int main()
{
int guess = 50;
char responst;
int min = 0, max = 101;
printf("选择一个从1到100的整数。我会尝试猜测它。\n");
printf("如果我的猜测是正确的，那么回应一个 y，如果它是错误的，则回答 n。\n");
printf("呃...你的号码是 %d?\n", guess);
while ((responst = getchar()) != 'y') //获取响应，与Y做对比
{
while (getchar() != '\n')
continue;
if (responst == 'n')
{
guess_a(&guess, &min, &max);
printf("恩，然后，它是 %d?\n", guess);
}
else
printf("对不起，我只懂y或n。\n");
}
printf("我知道我可以做到！\n");
system("pause");
return 0;
}
void guess_a(int *guess, int *min, int *max)
{
char ch;
bk:printf("我猜大了还是猜小了: \n");
printf("a.大了 \tb.小了\n");
scanf_s("%c", &ch);
while (getchar() != '\n')
continue;
if (ch == 'a')
{
*max = *guess;
*guess -= (*max - *min) / 2;
}
else if (ch == 'b')
{
*min = *guess;
*guess += (*max - *min) / 2;
}
else
{
printf("对不起，我只懂a或b。\n");
goto bk;
}
}
6
#include <stdio.h>
#include <ctype.h>
char get_first(void);
int main()
{
char ch;
ch = get_first();
putchar(ch);
putchar('\n');
system("pause");
return 0;
}
char get_first(void)
{
int ch;
while (!isalpha(ch = getchar()))
continue;
return ch;
}
7
#include <stdio.h> //标准输入输出函数库文件
#define MONEY1 8.75 //基本工资8.75美元/小时
#define MONEY2 9.33 //基本工资9.33美元/小时
#define MONEY3 10.00 //基本工资10.00美元/小时
#define MONEY4 11.20 //基本工资11.20美元/小时
#define HOUR 1.5 //超过40小时1.5倍
#define TAX1 300*0.15 //税率前300美元15%
#define TAX2 150*0.2 //续150美元为20%
#define TAX3 0.25 //余下的为25%
char ch_a(void);
int main()
{
double hour, money, money_1, tax;
int i;
b:printf("输入对应基本工资的编号：\n");
printf("a) $8.75/hr \tb)$9.33/hr\n");
printf("c) $10.00/hr \td)$11.20/hr\n");
printf("q) 退出\n");
i = ch_a();
switch (i)
{
case 'a':
money_1 = MONEY1;
break;
case 'b':
money_1 = MONEY2;
break;
case 'c':
money_1 = MONEY3;
break;
case 'd':
money_1 = MONEY4;
break;
case 'q':
goto quit;
default:
printf("输入错误请重新输入: \n");
goto b;
}
printf("请输入你的工作时间[小时]: ");
scanf_s("%lf", &hour);
if (hour <= 40)
money = hour * money_1;
else
money = (money_1 * 40) + (hour - 40)*HOUR*money_1;
if (money <= 300)
tax = money * 0.15;
else if (money <= 450)
tax = TAX1 + (money - 300)*0.2;
else
tax = TAX1 + TAX2 + (money - 450)*TAX3;
printf("你工作时间 %.2lf 小时, 工资总额: $%.2lf, 税金: $%.2lf, 净收入: $%.2lf.\n", hour, money, tax, money - tax);
quit:printf("完成再见！\n");
system("pause");
return 0;
}
char ch_a(void)
{
char ch, ch_a;
while ((ch = getchar()) != '\n')
{
if ((ch >= 'a'&&ch <= 'd') || ch == 'q')
ch_a = ch;
else
{
while (getchar() != '\n')
continue;
printf("输入有误, 请重新输入, 只能输入a, b, c, d或者q: \n");
continue;
}
}
return ch_a;
}
8
#include <stdio.h>
#include <ctype.h>
#define WIDTH 40
char ch_a(void);
float num(void);
void starbar(void);
int main()
{
float x, y;
char ch;
bk:starbar();
printf("输入您选择的操作: \n");
printf("a.加法 \t\ts.减法\nm.乘法 \t\td.除法\nq.退出\n");
starbar();
ch = ch_a();
if (ch == 'q')
goto done;
printf("请输入第一个数值: ");
x = num();
printf("请输入第二个数值: ");
y = num();
while (ch == 'd'&&y == 0)
{
printf("输入除0以外的数字: ");
y = num();
}
switch (ch)
{
case 'a':
printf("%g + %g = %g\n", x, y, x + y);
goto bk;
case 's':
printf("%g - %g = %g\n", x, y, x - y);
goto bk;
case 'm':
printf("%g x %g = %g\n", x, y, x * y);
goto bk;
case 'd':
printf("%g / %g = %g\n", x, y, x / y);
goto bk;
}
done:printf("\n再见\n");
system("pause");
return 0;
}
char ch_a(void)
{
char ch, ch_b;
ch_b = 0;
while ((ch = getchar()) != '\n')
{
if (ch == 'a' || ch == 's' || ch == 'm' || ch == 'd' || ch == 'q')
ch_b = ch;
else
{
while (getchar() != '\n')
continue;
printf("输入有误, 请重新输入, 只能输入a, s, m, d或者q: \n");
continue;
}
}
return ch_b;
}
float num(void)
{
float x;
char ch;
while (scanf_s("%f",&x) != 1)
{
while ((ch = getchar()) != '\n')
putchar(ch);
printf(" 不是一个数字.\n请重新输入, 例如2.5, -1.78E8或3: ");
continue;
}
while (getchar() != '\n')
continue;
return x;
}
void starbar(void)
{
int count;
for (count = 1; count <= WIDTH; count++)
putchar('*');
putchar('\n');
}
