实验二

实验任务1

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

#define N 5

int main()
{
int number, i;
srand(time(0));

for (i = 0; i < N; ++i) {
number = rand() % 500 + 1;
printf("20228329%04d\n", number);
}
return 0;
}

问题1：产生一个以时间为种子500及以内的随机数并赋值给number

问题2：产生一个根据时间变化的随机学号

实验任务2

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main()
{
int i=1,no, number;
srand(time(0));
printf("猜猜2022年11月哪一天会是你的lucky day");
printf("开始喽，你有三次机会，猜吧(1-30)：\n");
for(i=1;i<=3;i++)
{
scanf_s("%d", &no);
number = rand() % 30+1;
if (no < number)
printf("你猜的日期早了，你的lucky day还没到呢,再猜（1—30）\n");
else if (no > number)
printf("你猜的日期晚了，你的lucky day已经过了，再猜（1—30）\n");
else printf("\n");
}
printf("次数用完了，偷偷告诉你：11月你的幸运日期是%d", number);
return 0;
}

实验任务3

#include<stdio.h>
int main()
{
char no;
while (scanf_s("%c", &no) != EOF)
{
getchar();
switch (no) {
case 'y':printf("wait a minute\n"); break;
case 'g':printf("go go go\n"); break;
case 'r':printf("stop!\n"); break;
default:printf("something must be wrong\n"); break;
}

}
return 0;
}

实验任务4

 

#include <stdlib.h>

#include <stdio.h>

#include<math.h>

 

int main() {

    while (1) {

         double s, ans = 0.0;

         int k = 0;

         int n, a, i, m;

         scanf_s("%d %d", &n, &a);

         for (i = 1; i <= n; i++) {

             for (m = 1; m <= i; m++) {

                  k = a * (pow(10, m) - 1) / 9;

             }

             ans += double (i) / k;

         }

         printf("n=%d,a=%d,s=%lf \n", n, a, ans);

 

        

    }

    return 0;

}

 

 

实验任务5

 

#include<stdio.h>

int main()
{
int a, b;
for (a = 1; a <= 9; a++)
{
for (b = 1; b <= a; b++)printf("%dx%d=%2d ", b, a,a*b);
printf("\n");
}
return 0;
}

实验任务6

 

#include <stdlib.h>

#include <stdio.h>

#include<math.h>

 

int main() {

    int line,m,n,j;

    scanf_s("%d", &line);

    for (m = 1; m <= line; m++) {

         for (j = m; j > 1; j--) {

             printf("\t");

         }

         for (n = 2 * m - 1; n <= 2 * line - 1; n++) {

             printf(" o \t");

         }

         printf("\n");

         for (j = m; j > 1; j--) {

             printf("\t");

         }

         for (n = 2 * m - 1; n <= 2 * line - 1; n++) {

             printf("<H>\t");

         }

         printf("\n");

         for (j = m; j > 1; j--) {

             printf("\t");

         }

         for (n = 2 * m - 1; n <= 2 * line - 1; n++) {

             printf("I I\t");

         }

         printf("\n");

    }

   

    return 0;

}