实验二

#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()%100+1;
        printf("20490042%04d\n",number);
    }

    return 0;
}

#include <stdio.h>
int main() {
int choice, quantity;
float total_price = 0, amount_paid, change;
while (1) {
printf("\n自动饮料售卖机菜单:\n");
printf("1. 可乐 - 3 元/瓶\n");
printf("2. 雪碧 - 3 元/瓶\n");
printf("3. 橙汁 - 5 元/瓶\n");
printf("4. 矿泉水 - 2 元/瓶\n");
printf("0. 退出购买流程\n");
printf("请输入饮料编号: ");
scanf("%d", &choice);
if (choice == 0)
break;
if (choice < 1 || choice > 4) {
printf("无效的饮料编号，请重新输入。\n");
continue;
}
printf("请输入购买的数量: ");
scanf("%d", &quantity);
if (quantity < 0) {
printf("购买数量不能为负数，请重新输入。\n");
continue;
}
if(choice == 1 || choice == 2)
total_price += 3 * quantity;
else if(choice == 3)
total_price += 5 * quantity;
else
total_price += 2 * quantity;
printf("请投入金额: ");
scanf("%f", &amount_paid);
change = amount_paid - total_price;
printf("本次购买总价: %.2f 元\n", total_price);
printf("找零: %.2f 元\n", change);
total_price = 0;
}
printf("感谢您的购买，欢迎下次光临！\n");
return 0;
}

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

    }
}
    return 0;
 }

#include<stdio.h>
int main()
{
    double x,max,min,sum=0;
    int k=0;
    printf("输入今日开销，直到输入-1终止:\n");
    scanf("%lf",&x);
    if(x!=1)
    {
    max=x;
    min=x;
    }
    while(x!=-1){

    k++;
    sum+=x;
    if(x>max)
    max=x;
    if(x<min)
    min=x;
    scanf("%lf",&x);
    }
    printf("今日累计消费总额为：%.1f\n今日最高一笔开销：%.1f\n今日最低一笔开销：%.1f\n",sum,max,min);
        return 0;



}

#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||b*b+c*c==a*a||a*a+c*c==b*b)
        printf("直角三角形\n");

    else if(a==b||a==c||b==c){

       if(a==b&&b==c)
       printf("等边三角形\n");
       else
       printf("等腰三角形\n");
       }
    else
     printf("普通三角形\n");}
    return 0;

}

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main()
{
    int i,lucky_day,guess,chances=3;
    srand((unsigned int)time(NULL));
    lucky_day=rand()%30+1;
    printf("猜猜2026年4月哪一天是你的lucky day\n");
    printf("开始喽，你有3次机会，猜吧（1-30）：");
    for(i=1;i<=chances;i++){
      scanf("%d",&guess);
      if(guess==lucky_day){


      printf("哇，猜中了");
  return 0;}
     else if(guess>lucky_day){
         if(i< chances){

         printf("你猜的日期晚了");
         printf("再猜（1-30):");}
         else
         printf("你的次数用完了。四月你的lucky_day是%d号\n",lucky_day);


     }
     else{
         if(i< chances){

             printf("你的日期猜早了\n");
             printf("再猜（1-30):");
         }
         else
         printf("你的次数用完了。四月你的lucky_day是%d号\n",lucky_day);
     }



    }
    return 0;
}