实验二

task1

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define N 5
#define N1 80
#define N2 35
int main() {
    int cnt;
    int random_major, random_no;
    srand(time(NULL)); // 以当前系统时间作为随机种子
    cnt = 0;
    while (cnt < N) {
        random_major = rand() % 2;
        if (random_major) {
            random_no = rand() % N1 + 1;
            printf("20256343%04d\n", random_no);
        }
        else {
            random_no = rand() % N2 + 1;
            printf("20256136%04d\n", random_no);
        }
        cnt++;
    }
    return 0;
}

 问题一：使输出随机

问题二：随机生成五个学号

 

task2

#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;
}

 问题一：程序报错，无法运行

问题二：结束本次循环，开始下一次循环

 

 

task3

#include<stdio.h>
int main()
{
    char x;
    while (1)
    {
        x = getchar();
        if (x == 'r')
        {
            printf("stop!\n");
        }
        else if (x == 'g')
        {
            printf("go go go\n");
        }
        else if (x == 'y')
        {
            printf("wait a minute\n");
        }
        else
        {
            printf("something must be wrong\n");
        }
        getchar();
    }
    return 0;
}

 

 

task4

 

#include<stdio.h>
int main()
{
    double x=0,max=0,min=20000,sum=0;
    printf("输入今日开销，直到输入-1终止：\n");
    while(1)
    {
        scanf("%lf",&x);
        if (x == -1)
        {
            break;
        }
        sum += x;
        if (x > max)
        {
            max = x;
        }
        if (x < min)
        {
            min = x;
        }
    }
    printf("今日累计消费总额：%.1lf\n", sum);
    printf("今日最高一笔开销：%.1lf\n", max);
    printf("今日最低一笔开销：%.1lf\n", min);
    return 0;

}

 

 

 

task5

#include<stdio.h>
int main()
{
    int a, b, c;
    while (1)
    {
        scanf("%d %d %d", &a, &b, &c);
        if (a + b <= c || a + c <= b || b + c <= a)
        {
            printf("不能构成三角形");
        }
        else
        {
            if (a == b && b == c)
            {
                printf("等边三角形\n");
            }
            else if (a == b && a != c || a == c && a != b || b == c && a != b)
            {
                printf("等腰三角形\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");
            }
        }
    }
    return 0;
}

 

 

task6

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main()
{
    srand(time(NULL));
    printf("猜猜2025年11月那一天使你的lucky day\n开始咯，你有三次机会，猜吧（1-30):");
    int x =1+rand()%30, i = 0, a;
    while(1)
    {
        if (i == 2)
        {
            break;
        }
        scanf("%d", &a);
        getchar();
        if (a == x)
        {
            printf("哇，猜中了：）");
            break;
        }
        else if (a < x)
        {
            printf("你猜的日期早了，你的lucky day还没有到呢\n再猜（1-30）：");
        }
        else if (a>x)
        {
            printf("你猜的日期晚了，你的lucky day在前面哦\n再猜（1-30）：");
        }
        i++;
    } 
        getchar();
        printf("次数用光啦。偷偷告诉你，11月你的lucky day是%d号", x);
    return 0;
}