实验2

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;
}

去掉垓代码后，多次运行结果均相同，推测该代码作用为生成随机数

功能：随机选取学号

 

实验任务2

#define _CRT_SECURE_NO_WARNINGS
#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;
}

去除total_price = 0，会导致上一次的总价进入下一次循环

continue作用为结束当前循环，进入下一循环

 

实验任务3

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

 

实验任务4

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
int main() {
    double cost;
    double sum = 0, max = 0, min = 20000;
    printf("输入今日开销，直到输入-1终止：\n");
    while (1) {
        scanf("%lf", &cost);
        if (cost == -1)
        break;
        sum += cost;
        if (cost > max)
            max = cost;
        if (cost < min)
            min = cost;
        }
    printf("今日累计消费总和:%.1f\n", sum);
    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;
}

 

实验任务5

#define _CRT_SECURE_NO_WARNINGS
#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");
            continue;
        }
        if (a == b && a == 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 (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
            printf("普通三角形\n");


    }
    return 0;
}

 

实验设计6

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

        }
    }
    if (count == 3 && guess != luckyday)
        printf("次数用光啦。偷偷告诉你，11月你的luckyday是%d号\n", luckyday);
    return 0;
}