实验2

#include<stdio.h>
#include<stdlib.h>
#include<time.h>

#define N 5
#define N1 347
#define N2 465

int main()
{
    int number;
    int i;
    
    srand(time(0));
    
    for(i=0;i<N;++i)
    {
        number=rand()%(N2-N1+1)+N1;
        printf("202383290376%04d\n",number);
    }
    return 0;

}

#include<stdio.h>
int main()
{
    char n;
    while(scanf("%c",&n)!=EOF)
    {
        getchar();
        switch(n)
        {
        case 'r' : printf("srop!\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;
}

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main()
{
    int day,n,i;
    srand(time(0));
    day=rand()%(30)+1;
    printf("猜猜11月的那一天是你的lucky day\n");
    printf("开始喽，你有三次机会，猜吧（0~30）：");
    for (i=1;i<=3;i++)
    {
        scanf("%d",&n);
        if (n<day)
            printf("你的日期早了，你的lucky day还没到呢\n再猜（0~30）：");
        else if(n=day)
            printf("哇，猜中了:-)");
        else
            printf("你的日期晚了，你的lucky day已经过啦\n再猜（0~30）：");
     } 
     if (n!=day)
         printf("次数用完啦。偷偷告诉你，11月，你的lucky day是%d号",day);
    return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
    int n,a;
    while(scanf("%d%d",&n,&a)!=EOF)
    {

double down=0,s=0;
        int i;
        for(i=1;i<=n;++i)
        {
            down+=pow(10,i-1)*a;
            s+=i/down;
        }
        printf("n=%d,a=%d,s=%f",n,a,s);
    }
        return 0;
}

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

#include<stdio.h>
int main()
{
    int n = 0;
    int i;
    printf("input n :");
    scanf("%d", &n);
    for (i = 1; i <= n; i++)
    {
        int a1;
        for (a1 = 1; a1 <= 2 * i - 2; a1++)
        {
            printf("   ");
        }
        int a2;
        for (a2 = 1; a2 <= 2 * n - 2 * i + 1; a2++)
        {
            printf(" O    ");
        }
        printf("\n");
        for (a1 = 1; a1 <= 2 * i - 2; a1++)
        {
            printf("   ");
        }
        for (a2 = 1; a2 <= 2 * n - 2 * i + 1; a2++)
        {
            printf("<H>   ");
        }
        printf("\n");
        for (a1 = 1; a1 <= 2 * i - 2; a1++)
        {
            printf("   ");
        }
        for (a2 = 1; a2 <= 2 * n - 2 * i + 1; a2++)
        {
            printf("I I   ");
        }
        printf("\n\n");
    }

    return 0;
}