实验二

test 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;
}

test 2

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main()
{
    int number;
    int i;
    int n;
    srand(time(0));
    number = rand() % 30 + 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）：");

    for (i = 0; i < 3; ++i) {
        scanf_s("%d", &n);
        if (n == number) {
            printf("哇，你猜对了");
            break;
        }
        else if (n < number)
        {
            printf("你猜的日期早了，你的lucky day还没到呢\n再猜：");
        }
        else  (n > number);
        {
            printf("你猜的日期晚了，你的lucky day已经过了\n再猜：");
        }
    } printf("次数用完了。偷偷告诉你：11月，你的路lucky day是%d号",number);

       

    return 0;
}

test 3

#include <stdio.h>
int main()
{
    char n;
        do {
            n = getchar();
            getchar();
          if (n == 'r')
          {
              printf("stop!\n");
          }
          else if (n == 'g')
          {
              printf("go go go\n");
          }
          else if (n == 'y')
          {
              printf("wait a minute\n");
          }
          else {
            printf("something must be wrong\n");
        }
    } while (n != EOF);
    return 0;
}

test 4

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int main()
{
     double  s=0.0;
    int a, n;
    while (  scanf_s("%d%d", &n, &a) != EOF)
    {
        int t;
        printf("n=%d  a=%d\t", n, a);
        t = a;
        for (int i = 1; i <= n; i++)
        {
         
            s = s + i * 1.0 / t;
            t = 10 * t + a;
        }
        printf("s=%lf\n", s);
    }
    system("pause");
    return 0;

}

test 5

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int l, c, v;
    for (l = 1; l < 10; ++l)
    {
       
        for (c = 1; c <= l; ++c)
        {
            v = l * c;
            printf("%d*%d=%d\t",l,c,v);
        }
        printf("\n");
    }
    return 0;
}

test 6

#include<stdio.h>
int main()
{
    int n, i, j, a;
    printf("input:");
    scanf_s("%d", &n);
    for (j = 1; j <= n; j++)
    {
        for (a = 0; a <= j; a++)
        {
            printf("\t");
        }

        for (i = 0; i < 2 * (n - j) + 1; i++)
        {
            printf(" o \t");
        }
        printf("\n");
        for (a = 0; a <= j; a++)
        {
            printf("\t");
        }
        for (i = 0; i < 2 * (n - j) + 1; i++)
        {

            printf("<H>\t");
        }

        printf("\n");
        for (a = 0; a <= j; a++)
        {
            printf("\t");
        }
        for (i = 0; i < 2 * (n - j) + 1; i++)
        {
            printf("I I\t");
        }
        printf("\n");
    }
    return 0;
}