实验2 C语言分支与循环基础应用编程

task1.c

问题一：生成1~65中的随机数

问题二：随机生成5个本班学号

task2.c

#include <stdio.h>
int main()
{
    char colour;
    printf("请输入交通信号灯的颜色：");
    while ((colour = getchar()) != EOF)
    {
        switch (colour) 
        {
        case 'r':
            printf("stop!\n");
            break;
        case 'g':
            printf("go go go\n");
            break;
        case 'y':
            printf("wait a minute\n");
            break;
        default:
            printf("something must be wrong\n");
        }
        getchar();
    }
    return 0;
}

task3.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main()
{
    printf("猜猜2024年5月哪一天会是你的lucky day\n");
    int luckyday,guess,i;
    srand(time(0));
    luckyday = rand() % 31 + 1;
    printf("开始喽，你有三次机会，猜吧：");
    for (i = 0; i < 3; i++)
    {
        scanf("%d", &guess);
        if (guess == luckyday)
        {
            printf("猜中了\n");
            return 0;
        }
        else if (guess > luckyday)
                printf("猜晚了\n");
        else
                printf("猜早了\n");
    }
    if (i = 3)
        printf("次数用完啦，悄悄告诉你，5月你的lucky day是%d号", luckyday);

    return 0;
}

 

 task4.c

#include <stdio.h>
int main()
{
    double s = 0,down=0;
    int i,n,a;
    while (scanf("%d%d", &n, &a) != EOF)
    {
        for (i = 1; i <= n; i++)
        {
            down = 10 * down + (double)a;
            s += i / down;
        }
        printf("s=%lf\n", s);
        s = 0;
        down = 0;
    }
    return  0;
}

 

task5.c

#include <stdio.h>
int main()
{
    int column, line, value;
    for (column = 1; column <= 9; column++)
    {
        for (line = 1; line <= column; line++)
        {
            value = column * line;
            printf("%dx%d =%4d  ", line, column, value);
            if (line == column)
                printf("\n");
        }
    }
    return 0;
}

 

task6.c

#include <stdio.h>
int main()
{
    int n,i,j;
    scanf("%d", &n);
    for (i=n;i>0;i--)
    {
        for (j = 0; j < n - i; j++)
        {
            printf("   \t");
        }
        for (j = 0; j < (2 * i - 1); j++)
        {
            printf(" O \t");
        }
        printf("\n");
        for (j = 0; j < n - i; j++)
        {
            printf("   \t");
        }
        for (j = 0; j < (2 * i - 1); j++)
        {
            printf("<H>\t");
        }
        printf("\n");
        for (j = 0; j < n - i; j++)
        {
            printf("   \t");
        }
        for (j = 0; j < (2 * i - 1); j++)
        {
            printf("I I\t");
        }
        printf("\n");
        
    }
    return 0;
}