【C Primer Plus】编程练习第七章

1、

#include <stdio.h>
#include <string>

int main()
{
    char ch;
    int space_1 = 0;
    int break_1 = 0;
    int other_1 = 0;
    printf("请输入字符：");
    while ((ch=getchar()) != '#')
    {
        if (ch == ' ')
            space_1++;
        else if (ch == '
')
            break_1++;
        else
            other_1++;
        
    }
    printf("空格有%d个，换行符有%d个，其他字符有%d个", space_1, break_1, other_1);

    getchar();
    getchar();
    return 0;
}

2、

#include <stdio.h>
#include <string>

int main()
{
    char ch = 0;
    int i = 0;

    printf("请输入字符:");
    while ((ch = getchar()) != '#')
    {
        if ((i % 8 == 0) && (i != 0))
        {
            putchar('
');
        }
        i++;
        if (ch != '
')
            printf("%c:%d ", ch, ch);
    }
    getchar();
    getchar();
    return 0;
}

3、

#include <stdio.h>
#include <string>

int main()
{
    int i = 0;
    int odd = 0;
    int even = 0;
    int sum_e = 0;
    int sum_o = 0;

    printf("请输入整数:");
    while (scanf("%d",&i))
    {
        if (i == 0) {
            break;
        }
        else if ((i % 2) == 0) {    
            even++;
            sum_e = i + sum_e;
        }
        else {
            odd++;
            sum_o = i + sum_o;
        }
    }
    printf("输入的偶数个数有%d,偶数平均值为%f,输入的奇数个数有%d,奇数平均值为%f", even, (float)(sum_e / even), odd, (float)(sum_o / even));

    getchar();
    getchar();
    return 0;
}

 

4、

#include <stdio.h>
#include <string>

int main()
{
    char ch = { 0 };
    printf("请输入字符：");
    while ((ch = getchar()) != '#')
    {
        if (ch == '.') {
            putchar('!');
        }
        else if (ch == '!') {
            putchar('!');
            putchar('!');
        }
        else
            putchar(ch);
    }

    getchar();
    getchar();
    return 0;
}

 

5、

#include <stdio.h>
#include <string>

int main()
{
    char ch = { 0 };
    printf("请输入字符：");
    while ((ch = getchar()) != '#')
    {
        switch (ch)
        {
        case '.':
            putchar('!');
            continue;
        case '!':
            putchar('!');
            putchar('!');
            continue;

        default:
            putchar(ch);
            continue;
        }
    }

    getchar();
    getchar();
    return 0;
}

 

6、

#include <stdio.h>
#include <string>

int main()
{
    int n = 0;
    char ch = 0;
    char ch_p = 0;
    printf("请输入字符：");
    while ((ch = getchar()) != '#')
    {
        if (ch == 'i') {
            if (ch_p == 'e') {
                n++;
            }
        }
        ch_p = ch;
    }
    printf("ei出现了%d次", n);
    getchar();
    getchar();
    return 0;
}

 

7、

#include <stdio.h>
#include <string>
#define BASIC 10
#define PLUS 1.5
#define TAX_1 0.15
#define TAX_2 0.2
#define TAX_3 0.25

int main()
{
    int t = 0;
    double wage, tax, income;
    printf("请输入一周工作小时数：");
    while (scanf("%d", &t)) {
        if (t <= 40) {
            wage = BASIC * t;
            if (wage <= 300) {
                tax = wage * TAX_1;
                income = wage - tax;
            }
            else {
                tax = 300 * TAX_1 + (wage - 300) * TAX_2;
                income = wage - tax;
            }
        }
        else {
            wage = 400 + (t - 40)*PLUS*BASIC;
            if (wage <= 450) {
                tax = 300 * TAX_1 + (wage - 300)*TAX_2;
                income = wage - tax;
            }
            else {
                tax = 300 * TAX_1 + 150 * TAX_2 + (wage - 450)*TAX_3;
                income = wage - tax;
            }
        }
        printf("你工作了%d小时，工资总额为%lf,税金为%lf,净收入为%lf
", t, wage, tax, income);
        printf("请输入一周工作小时数：");
    }
    
    getchar();
    getchar();
    return 0;
}

 

8、

#include <stdio.h>
#include <string>
#define PLUS 1.5
#define TAX_1 0.15
#define TAX_2 0.2
#define TAX_3 0.25

int main()
{
    int choice = 0;
    double basic = 0;
    int t = 0;
    double wage = 0;
    double tax = 0; 
    double income = 0;
    printf("******************************************************************
");
    printf("Enter the number corresponding to the desired pay rate or action：
");
    printf("1)$8.75/hr                              2)$9.33/hr
");
    printf("3)$10.00/hr                             4)$11.20/hr
");
    printf("5)quit
");
    printf("******************************************************************
");
    printf("请输入工资等级:");
    while (scanf("%d", &choice)&&(choice<=4)) {
        switch (choice)
        {
        case 1:
            basic = 8.75;
            break;
        case 2:
            basic = 9.33;
            break;
        case 3:
            basic = 10.00;
            break;
        case 4:
            basic = 11.20;
            break;
        case 5:
            break;
        default:
            printf("请输入数字1到5，谢谢！");
            break;
        }
        printf("请输入一周工作小时数：");
        scanf("%d", &t);

        if (t <= 40) {
            wage = basic * t;
            if (wage <= 300) {
                tax = wage * TAX_1;
                income = wage - tax;
            }
            else {
                tax = 300 * TAX_1 + (wage - 300) * TAX_2;
                income = wage - tax;
            }
        }
        else {
            wage = 400 + (t - 40)*PLUS*basic;
            if (wage <= 450) {
                tax = 300 * TAX_1 + (wage - 300)*TAX_2;
                income = wage - tax;
            }
            else {
                tax = 300 * TAX_1 + 150 * TAX_2 + (wage - 450)*TAX_3;
                income = wage - tax;
            }
        }
        printf("你工作了%d小时，工资总额为%lf,税金为%lf,净收入为%lf
", t, wage, tax, income);
        printf("请输入工资等级:");
    }
    
    getchar();
    getchar();
    return 0;
}

 

9、

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int isprimer(int n);
int main() {
    int n;
    while (1)
    {
        printf("请输入一个数：
");
        scanf("%d", &n);
        if (isprimer(n))
            printf("%d
", n);
        else
        {
            printf("这不是一个素数！
");
        }
    }
    system("pause");
    return 0;
}
int isprimer(int n) {
    for (int i = 2; i < n; i++) {
        if (n%i == 0)
            return 0;
    }
    return 1;
}