作业二

任务一

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

#define N 5
#define N1 397
#define N2 476
#define N3 21

int main() {
    int cnt;
    int random_major, random_no;
    
    srand(time(NULL)); 
 
     cnt = 0;
    while(cnt < N) {
        random_major = rand() % 2;
        
        if(random_major) {
            random_no = rand() % (N2 - N1 + 1) + N1;
            printf("20248329%04d\n", random_no);
     }
    else {
            random_no = rand() % N3 + 1;
            printf("20248395%04d\n", random_no);
     }
        cnt++;
     }
     return 0;
}

问题一

随机生成一个数范围为[397,476]

问题二

随机生成一个数范围为[1,21]

问题三

随机抽取学号

 

任务二

#include <stdio.h>
#include <math.h>
int main() {
    double a, b, c;
     double delta, p1, p2; 
     while(scanf("%lf%lf%lf", &a, &b, &c) != EOF) {
         if(a == 0) {
             printf("a = 0, invalid input\n");
             continue;
          }
         delta = b*b - 4*a*c;
         p1 = -b/2/a;
         p2 = sqrt(fabs(delta))/2/a;
         if(delta == 0)
             printf("x1 = x2 = %.2g\n", p1);
         else if(delta > 0)
             printf("x1 = %.2g, x2 = %.2g\n", p1+p2, p1-p2);
         else {
             printf("x1 = %.2g + %.2gi, ", p1, p2);
             printf("x2 = %.2g - %.2gi\n", p1, p2);
         }
      }
    return 0;
}

 

任务三

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

 

任务四

#include<stdio.h>
int main (){
double tot,max,min,e,c;
    printf("输入今日开销，直至输入-1终止：\n"); 
    tot=0;
    max=0;
    min=2000;
    while(scanf("%lf",&e)!=EOF){
        tot=tot+e;
        
        getchar();
    if (e==-1)
        break ;
    if (e>max)
        max=e;
    if (e<min)
       min=e;
    
        }
        
        printf("今日累计消费总额：%lf\n",tot);
        printf("今日最高一笔开销：%lf\n",max);
        printf("今日最低一笔开销：%lf\n",min);
        
        return 0;
}

 

任务五

#include<stdio.h>
int main(){
int a,b,c;
    while(scanf("%d%d%d",&a,&b,&c) !=EOF){
        if((a+b<=c)||(a+c<=b)||(b+c<=a))
        {printf("不能构成三角形\n");
        }
        else{
            if((a*a+b*b==c*c)||(a*a+c*c==b*b)||(b*b+c*c==a*a)){
            printf("直角三角形\n");
            }
            else if((a==b)&&(b==c)){
                printf("等边三角形\n");
            }
            else if((a==b)||(b==c)||(c==a)){
                printf("等腰三角形\n");
            }
            else {printf("普通三角形\n");
            }
        }
    }
    return 0;
}

 

任务六

#include<stdlib.h>
#include<stdio.h>
#include<time.h>
int main(){
    srand(time(NULL));
    int guess,cnt=0,luckyday;

    luckyday=rand()%30+1;
    printf("猜猜十一月哪一天会是你的lucy day，你有三次机会\n");
    while (scanf("%d",&guess) !=EOF){
        if(guess==luckyday){
            printf("恭喜你猜中啦！");
            return 0;}
        else if(cnt<2) {
         
        
        if(guess>luckyday){
            printf("猜晚啦，再来一次吧！\n");
            cnt+=1; 
        }
        else if(guess<luckyday){
        printf("猜早啦，再来一次吧！\n");
        cnt+=1;}
        }
         else{
        printf("次数用光喽！你的lucky day其实是%d",luckyday); 
        return 0;}
    }
    return 0;
}