实验2

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define N 5
int main()
{
    int number;
    int i;
    srand(time(0));
    for (i = 0; i < N; ++i)
    {
        number = rand() % 500 + 1;
        printf("20228329%04d\n", number);
    }
    return 0;
}

 随机取一个在1~501的数。用来抽签什么的。

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main()
{
    int i, j, m;
    srand(time(0));
    j = rand() % 29 + 1;
    printf("猜猜2022年11月哪一天会是你的lucky day\n");
    printf("开始喽，你有三次机会，猜吧（1~30):");
    scanf_s("%d", &i);
    for (m = 1; m <= 2; m++)
    {
        if (i > j)
        {
            printf("你猜的日期晚了，你的lucky day已经过啦\n");
            printf("再猜：");
            scanf_s("%d", &i);
        }
        else if (i < j)
        {
            printf("你猜的日期早了，你的lucky day还没到呢\n");
            printf("再猜：");
            scanf_s("%d",&i);
        }
        else
        {
            printf("哇，猜中了:-)");
            break;
        }
    }
    if (m == 3)
    {
        printf("次数用完啦，偷偷告诉你：11月，你的lucky day是%d", j);
    }
    return 0;
}

#include<stdio.h>
#include<stdlib.h>
int main()
{
    char a;
    while (scanf_s("%c",&a)!=EOF)
    {
        switch (a)
        {
        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"); break;
        }
        getchar();
    }
    return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
    int n, a,b;
    double j, s = 0.0;
    while (scanf_s("%d%d", &n, &a) != EOF)
    {
        b = a;
        printf("n=%d,a=%d", n, a);
        for (j = 1.0; j <= n; j++)
        {
            s += j /b;
            b = b * 10 + a;
        }
        printf(" s=%lf\n", s);
        s = 0;
    }
    return 0;
}

#include<stdio.h>
int main()
{
    int a, b,c;
    for (a = 1; a <= 9; a++)
    {
        for (b = 1; b <=a; b++)
        {
            c = b * a;
            printf("%d*%d=%d \t",b,a,c);
        }
        printf("\n");
    }
    return 0;
}

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