实验2

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <time.h>
 4 
 5 #define N 5
 6 #define N1 397
 7 #define N2 476
 8 #define N3 21
 9 
10 int main() {
11     int cnt;
12     int random_major, random_no;
13 
14     srand(time(NULL));      
15 
16     cnt = 0;
17     while(cnt < N) {
18         random_major = rand() % 2;
19 
20         if(random_major) {
21             random_no = rand() % (N2 - N1 + 1) + N1;
22             printf("20248329%04d\n", random_no);
23         }
24         else {
25             random_no = rand() % N3 + 1;
26             printf("20248395%04d\n", random_no);
27         }
28 
29         cnt++;
30     }
31 
32     return 0; 
33 }

随机生成0397到0476间的数字

随机生成0001到0021间的数字

随机抽出几个学号

任务二

 1 #include <stdio.h>
 2 #include <math.h>
 3 
 4 int main() {
 5     double a, b, c;
 6     double delta, p1, p2; 
 7 
 8     while(scanf("%lf%lf%lf", &a, &b, &c) != EOF) {
 9         if(a == 0) {
10             printf("a = 0, invalid input\n");
11             continue;
12         }
13 
14         delta = b*b - 4*a*c;
15         p1 = -b/2/a;
16         p2 = sqrt(fabs(delta))/2/a;
17 
18         if(delta == 0)
19             printf("x1 = x2 = %.2g\n", p1);
20         else if(delta > 0)
21             printf("x1 = %.2g, x2 = %.2g\n", p1+p2, p1-p2);
22         else {
23             printf("x1 = %.2g + %.2gi, ", p1, p2);
24             printf("x2 = %.2g - %.2gi\n", p1, p2);
25         }
26     }
27 
28     return 0;
29 }

任务三：

 1 #include<stdio.h>
 2 
 3 int main(){
 4     char c;
 5     
 6     while(scanf("%c",&c)!=EOF){
 7         if(c=='r')
 8            printf("stop!\n");
 9         else if(c=='g')
10            printf("go go go\n");
11         else if(c=='y')
12            printf("wait a minute\n");
13         else
14            printf("something must be wrong\n");
15         getchar();
16     }
17     
18     return 0;
19 }

任务四

 1 #include<stdio.h>
 2 int main(){
 3     double x,sum=0,max,min;
 4     max=x;
 5     min=x;
 6     printf("输入今日开销，直到输入-1终止：\n");
 7     scanf("%lf",&x);
 8     while(x>0){
 9         sum=sum+x;
10         if(x>max)
11            max=x;
12         else
13            min=x;
14            
15         scanf("%lf",&x);
16     
17     }
18 
19 
20     printf("今日累计消费总额：%.1lf\n",sum);
21     printf("今日最高一笔开销：%.1lf\n",max);
22     printf("今日最低一笔消费：%.1lf\n",min);
23 }

任务五

 1 #include <stdio.h>
 2 int main(){
 3     int a,b,c;
 4     while(scanf("%d%d%d",&a,&b,&c)!=EOF){
 5         if(a+b<=c||a+c<=b||b+c<=a)
 6            printf("不能构成三角形\n");
 7         else if(a*a+b*b==c*c||a*a+c*c==b*b||b*b+c*c==a*a)
 8            printf("直角三角形\n");
 9         else if(a==b&&a==c&&b==c)
10            printf("等边三角形\n"); 
11         else if(a==b||a==c||b==c)
12            printf("等腰三角形\n");
13         else 
14            printf("普通三角形\n");
15     }             
16     
17    return 0;
18     
19 }

任务六

 1 #include <stdio.h>
 2 #include <stdlib.h> 
 3 int main(){
 4 printf("猜猜2024年11月哪一天会是你的lucky day\n");
 5 printf("开始喽，你有三次机会,猜吧(1~30):" );
 6 int n,ans,input;
 7 n=0;
 8 ans=rand()%30+1;
 9 while(n!=3){
10 
11 scanf("%d",&input);
12 if (input>ans){
13 printf("你猜的日期晚了，你的lucky day在前面哦\n");
14 
15 }
16 else if(input<ans){
17 printf("你猜的日期早了，你的lucky day还没到呢\n");
18 
19 }
20 else if(input==ans){
21 printf("哇，猜中了");
22 break;
23 }    
24 n=n+1;
25 if(n<=2){
26 
27 printf("再猜(1~30):");}
28 }
29 if(n==3){
30 printf("次数用光啦。偷偷告诉你，11月你的lucky day是%d号",ans);
31     
32 }
33 }