实验2

实验结论

1.实验任务1

#define _CRT_SECURE_NO_WARNINGS
#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1  重新生成随机数，去掉后生成的结果都是相同的

       问题2  生成随机的学生学号

2.实验任务2

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.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1  去掉后，后面购买的总价将会加上上一次的总价

问题2   跳过此次循环，开始下一次循环

3.实验任务3

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

　　

 4.实验任务4

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



    return 0;
}

　　

 5.实验任务5

#define  _CRT_SECURE_NO_WARNINGS

#include <stdio.h>
int main() {
    int a, b, c;
    int x, y, z;
    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");
            continue;
        }
        x = a * a;
        y = b * b;
        z = c * c;
        if (a == b && b == c)
            printf("等边三角形\n");
        else if (a == b || a == c || b == c)
            printf("等腰三角形\n");
        else if (x + y == z || x + z == y || y + z == x)
            printf("直角三角形\n");
        else
            printf("普通三角形\n");
    }
    return 0;
}

　　

 6.实验任务6

#define  _CRT_SECURE_NO_WARNINGS
#include<stdlib.h>
#include <stdio.h>
#include<time.h>
int main() {
    srand(time(NULL));
    int luckyday = rand() % 30 + 1;
    int i = 0, guess;
    printf("猜猜2025年11月哪一天是你的lucky day\n");
    printf("开始喽，你有三次机会，猜吧（1~30)：");
    while (1) {
        i++;
        scanf("%d", &guess);
        getchar();
        if (guess < luckyday)
            printf("你猜的日期早了，你的lucky day还没到呢\n");
        else if (guess > luckyday) 
            printf("你猜的日期晚了，你的lucky day在前面哦\n");
        else{
            printf("哇，猜中了：）\n");
            break;}
        if (i == 3) {
            printf("次数用光啦。偷偷告诉你，11月你的lucky day是%d号", luckyday);
            break;
        }
        printf("再猜（1~30）：");
    }
    return 0;
}