实验2

1. #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;
}
2. #include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main()
{   
    int y;
    int i;
    srand(time(0));
    int x = rand() % 31+1;
    printf("猜猜2022年11月那天是你的lucky day,开始了，你有三次机会，猜吧：");
    for (i = 1; i < 4; i++)
    {
        scanf_s("%d", &y);
        if (y == x)
        {
            printf("哇，猜中了");
            return 0;
        }
        else if (y < x)
            printf("你猜的日期早了，你的lucky day还没到呢！再猜");
        else
            printf("你猜的日期晚了，你的lucky day已经过了，再猜");
     }
    if (i >= 4)
        printf("次数用完了，偷偷告诉你吧，11月%d", x);
    return 0;
}3. #include<stdio.h>
int main()
{
    char color;
    printf("请输入交通信号灯颜色：r表示red,g表示green,y表示yellow\n");
    while (scanf_s("%c", &color) != EOF)
    {
        getchar();
        switch (color)
        {
        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;
        }
        
    }
    return 0;

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

}
5. #include<stdio.h>
#include<stdlib.h>
int main()
{
    unsigned int n, m, ans;
    int k, i, p;
    n = 0, m = 1, p = 1;
    ans = m * n;
    for (k = 1; k <= 9; ++k, ++p) {
        n = 0;
        for (i = 1; i <= p; ++i)
        {
            n++;
            ans = n * m;
            printf("%dx%d=%2d  ", n, m, ans);
        }
        m++;
        printf("\n");
    }
    system("pause");
    return 0;
}
6. #include<stdio.h>
#include<stdlib.h>
int main()
{ int n,i ,j,k,c,b,l;
    printf("input n:");
    scanf_s("%d",&n);
    k=0,b=0,l=0;
    for(j=1;j<=n;n--)
    {   
        for(c=1;c<=k;c++)
        {printf("        ");}
        for(i=1;i<=2*n-1;i++)
        {
            printf("  o  \t");
        }
        printf("\n");
        for(c=1;c<=b;c++)
        {printf("        ");}
        for(i=1;i<=2*n-1;i++)
        {
            printf(" <H> \t");
        }
        printf("\n");
        for(c=1;c<=l;c++)
        {printf("        ");}
        for(i=1;i<=2*n-1;i++)
        {
            printf(" I I \t");}
        printf("\n");
}