2.

#define _USE_MATH_DEFINES#include 
     
      #include 
      
       #include 
       
        using namespace std;int main(){    float r, h, l, S, S1, V, V1;    cin >> r >> h;    l = 2 * M_PI * r;    S = M_PI * r * r;    S1 = 4 * M_PI * r * r;    V = 4 / 3 * M_PI * r * r * r;    V1 = S * h;    cout << setiosflags(ios::fixed) << setprecision(2);    cout << "圆周长 l = " << l << '\t' << "圆面积 S = " << S << endl;    cout << "圆球表面积 S1 = " << S1 << '\t' << "圆球体积 V = " << V << endl;    cout << "圆柱体积 V1 = " << V1 << endl;    return 0;}
       
      
     

 

结果：

 

3.

#include 
     
      #include 
      
       using namespace std;int main(){    float F, c;    cout << "华氏温度 F = ";    cin >> F;    cout << setiosflags(ios::fixed) << setprecision(2);    c = (5.0 / 9.0) * (F - 32);    cout << "摄氏温度c = " << c << endl;    return 0;}
      
     

 

结果：

 

 4.

c1,c2定义为字符型

#include 
     
      using namespace std;int main(){    char c1, c2;    cout << "请输入两个字符";    c1 = getchar();    c2 = getchar();    cout << "putchar 输出结果";    putchar(c1);    putchar('\t');    putchar(c2);    putchar('\n');    cout << "cout输出结果";    cout << c1 << '\t' << c2 << endl;    return 0;}
     

 

结果：

 

c1,c2定义为整形

#include 
     
      using namespace std;int main(){    int c1, c2;    cout << "请输入两个字符";    c1 = getchar();    c2 = getchar();    cout << "putchar 输出结果";    putchar(c1);    putchar('\t');    putchar(c2);    putchar('\n');    cout << "cout输出结果";    cout << c1 << '\t' << c2 << endl;    return 0;}
     

 

结果：

定义为整形即可输出ASCII码。

 

8.

0

1

1

0

1

 

9.

#include 
     
      using namespace std;int main(){    int compare(int x, int y, int z);    int a, b, c, temp, max;    cout << "输入三个整数a b c" << endl;    cin >> a >> b >> c;    //第一种方法    /*if ((a > b) && (a > c))    cout << "最大的数为a = " << a << endl;    else if((b>a)&&(b>c))    cout << "最大的数为b = " << b << endl;    else    cout << "最大的数为c = " << c << endl;*/    //第二种方法    /*if(a
      
        y) ? x : y;    max = (temp > z) ? temp : z;    return max;}
      
     

 

结果：

 

10.

#include 
     
      using namespace std;int main(){    int x, y;    cout << "输入 x = ";    cin >> x;    if (x < 1)        y = x;    else        if (x >= 1 && x < 10)            y = 2 * x - 1;        else            y = 3 * x - 11;    cout << "输出 y = " << y << endl;    return 0;
     

 

结果：

 

11.

#include 
     
      using namespace std;int main(){    int grade;    while (1)    {        cout << "输入学生成绩grade = ";        cin >> grade;        if (grade < 0 || grade > 100)            cout << "成绩输入错误,请重新输入！" << endl;        else            switch ((int)grade / 10)            {            case 10: cout << grade << "分成绩等级为A" << endl; break;            case 9: cout << grade << "分成绩等级为A" << endl; break;            case 8: cout << grade << "分成绩等级为B" << endl; break;            case 7: cout << grade << "分成绩等级为C" << endl; break;            case 6: cout << grade << "分成绩等级为D" << endl; break;            default: cout << grade << "分成绩等级为E" << endl; break;            }    }    return 0;}
     

 

结果：

 

12.

#include 
     
      using namespace std;int main(){    long int a;    cout << "输入正整数 a = ";    while (1)    {        cin >> a;        if (a > 99999)        {            cout << "输入错误,请重新输入！" << endl;            continue;        }        else if (a / 10000 > 0)            cout << "a 为5位数 " << a / 10000 + (a % 10000) / 1000 * 10 + (a % 1000) / 100 * 100 + (a % 100) / 10 * 1000 + (a % 10) * 10000 << endl;        else if (a / 1000 > 0)            cout << "a 为4位数 " << a / 1000 + (a % 1000) / 100 * 10 + (a % 100) / 10 * 100 + (a % 10) * 1000 << endl;        else if (a / 100 > 0)            cout << "a 为3位数 " << a / 100 + (a % 100) / 10 * 10 + (a % 10) * 100 << endl;        else if (a / 10 > 0)            cout << "a 为2位数 " << a / 10 + (a % 10) * 10 << endl;        else            cout << "a 为1位数 " << a << endl;    }    return 0;}
     

 

结果：

 

13.

 

#include
     
      using namespace std;int main(){    float i;    int c;    while (1)    {        /*cout << "输入当月利润为 i = ";        cin >> i;        if (i <= 10)        cout << "应发奖金为 " << i*0.1 << "万元" << endl;        else if (i <= 20 && i >= 10)        cout << "应发奖金为 " << 10 * 0.1 + (i - 10)*0.075 << "万元" << endl;        else if (i <= 40 && i >= 20)        cout << "应发奖金为 " << 10 * 0.1 + 10 * 0.075 + (i - 20)*0.05 << "万元" << endl;        else if (i <= 60 && i >= 40)        cout << "应发奖金为 " << 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + (i - 40)*0.03 << "万元" << endl;        else if (i <= 100 && i >= 60)        cout << "应发奖金为 " << 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + 20 * 0.03 + (i - 60)*0.015 << "万元" << endl;        else        cout << "应发奖金为 " << 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + 20 * 0.03 + 40 * 0.015 + (i - 100)*0.01 << "万元" << endl;*/        cout << "输入当月利润为 i = ";        cin >> i;        c = i / 10;        if (c > 10) c = 10;        switch (c)        {        case 0: cout << "应发奖金为 " << i*0.1 << "万元" << endl; break;        case 1: cout << "应发奖金为 " << 10 * 0.1 + (i - 10)*0.075 << "万元" << endl; break;        case 2:        case 3: cout << "应发奖金为 " << 10 * 0.1 + 10 * 0.075 + (i - 20)*0.05 << "万元" << endl; break;        case 4:        case 5: cout << "应发奖金为 " << 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + (i - 40)*0.03 << "万元" << endl; break;        case 6:        case 7:        case 8:        case 9: cout << "应发奖金为 " << 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + 20 * 0.03 + (i - 60)*0.015 << "万元" << endl; break;        case 10: cout << "应发奖金为 " << 10 * 0.1 + 10 * 0.075 + 20 * 0.05 + 20 * 0.03 + 40 * 0.015 + (i - 100)*0.01 << "万元" << endl; break;        }    }    return 0;
     

 

结果：

 

14.

#include
     
      using namespace std;int main(){    void sort(int m, int j, int k, int l);    int a, b, c, d;    cout << "请输入四个整数 ";    cin >> a >> b >> c >> d;    sort(a, b, c, d);    return 0;}void sort(int m, int j, int k, int l){    int temp;    if (m > j) { temp = m; m = j; j = temp; }    if (m > k) { temp = m; m = k; k = temp; }    if (m > l) { temp = m; m = l; l = temp; }    if (j > k) { temp = j; j = k; k = temp; }    if (j > l) { temp = j; j = l; l = temp; }    if (k > l) { temp = k; k = l; l = temp; }    cout << "从小到大顺序输出为：" << m << '\t' << j << '\t' << k << '\t' << l << '\t' << endl;}
     

 

结果：

 

15.

#include
     
      using namespace std;int main(){    int m, n, temp, p;    while (1)    {        temp = 1;        cout << "请输入两个正整数：";        cin >> m >> n;        p = m * n;        while (temp != 0)        {            if (m > n)            {                temp = m % n;                m = n; n = temp;                if (temp == 0)                {                    cout << "m 和 n 的最大公约数为：" << m << endl;                    cout << "m 和 n 的最小公倍数为：" << p / m << endl;                }            }            else            {                temp = n % m;                n = m; m = temp;                if (temp == 0)                {                    cout << "m 和 n 的最大公约数为：" << n << endl;                    cout << "m 和 n 的最小公倍数为：" << p / n << endl;                }            }        }    }    return 0;}
     

 

结果：

 

16.

#include 
     
      using namespace std;int main(){    char c;    int l = 0, s = 0, d = 0, o = 0;    cout << "请输入一行字符" << endl;    while (1)    {        while ((c = getchar()) != '\n')        {            if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z')                l++;            else if (c == ' ')                s++;            else if (c >= '0' && c <= '9')                d++;            else                o++;        }        cout << "这一行字符中" << "英文字母" << l << "个" << endl;        cout << "这一行字符中" << "空格" << s << "个" << endl;        cout << "这一行字符中" << "数字" << d << "个" << endl;        cout << "这一行字符中" << "其他字符" << o << "个" << endl;        l = 0, s = 0, d = 0, o = 0;    }return 0;}
     

结果：

 

17.

 

#include
     
      using namespace std;int main(){    int a, Sn = 0, n, i = 1, temp = 0;    cout << "输入 a 的值: ";    cin >> a;    cout << "输入 n 的值: ";    cin >> n;    while (i <= n)    {        temp = temp + a;        Sn = Sn + temp;        a = a * 10;        i++;    }    cout << "Sn = " << Sn << endl;    return 0;}
     

结果：

 

18.

#include
     
      using namespace std;int main(){    int n = 1, S = 0, temp = 1;    while (n <= 20)    {        temp = temp*n;        S = S + temp;        n++;    }    cout << S << endl;    return 0;}
     

 

结果：

 

19.

#include
     
      using namespace std;int main(){    int a, b, i, j, k;    for (a = 100; a < 1000; a++)    {        i = a / 100;        j = (a % 100) / 10;        k = a % 10;        b = i*i*i + j*j*j + k*k*k;        if (a == b)            cout << a << " 是水仙花数" << endl;    }    return 0;}
     

结果：

 

20.

#include 
     
      using namespace std;int main(){    int m, n, i;    for (m = 2; m<1000; m++)    {        n = 0;        for (i = 1; i
     

结果：

 

21.

#include 
     
      using namespace std;int main(){    int i, t, n = 20;    double a = 2, b = 1, s = 0;    for (i = 1; i <= n; i++)    {        s = s + a / b;        t = a;        a = a + b; // 将前一项分子与分母之和作为下一项的分子        b = t; // 将前一项的分子作为下一项的分母    }    cout << "sum=" << s << endl;    return 0;}
     

结果：

 

22.

#include 
     
      using namespace std;int main(){    int n = 1, i;    for (i = 1; i < 10; i++)    {        n = (n + 1) * 2;    }    cout << "桃子总数" << n << endl;    return 0;}
     

结果：

 

23.

#include 
     
      #include 
      
       using namespace std;int main(){    float a, x0, x1;    cout << "enter a positive number: ";    cin >> a;     x0 = sqrt(double(a));    x1 = (x0 + a / x0) / 2;    do    {        x0 = x1;        x1 = (x0 + a / x0) / 2;    }    while (fabs(x0 - x1) >= 1e-5);    cout << "The square root of " << a << " is " << x1 << endl;    return 0;}
      
     

 

结果：

 

24.

#include 
     
      using namespace std;int main(){    int i, k;    for (i = 0; i <= 3; i++) // 输出上面4行*号    {        for (k = 0; k <= 2 * i; k++)            cout << "*"; // 输出*号        cout << endl; //输出完一行*号后换行    }    for (i = 0; i <= 2; i++) // 输出下面3行*号    {        for (k = 0; k <= 4 - 2 * i; k++)            cout << "*"; // 输出*号        cout << endl; // 输出完一行*号后换行    }    return 0;}
     

结果：

 

 

25.

#include 
     
      using namespace std;int main(){    char i, j, k; /* i是a的对手;j是b的对手;k是c的对手*/    for (i = 'X'; i <= 'Z'; i++)        for (j = 'X'; j <= 'Z'; j++)            if (i != j)                for (k = 'X'; k <= 'Z'; k++)                    if (i != k && j != k)                        if (i != 'X' && k != 'X' && k != 'Z')                            cout << "A--" << i << " B--" << j << " C--" << k << endl;    return 0;}
     

结果：

 

参考链接：