实验2

实验任务1

#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
使得生成分别以20256343和20256136为前缀的学号的个数随机，每次二者的的在生成的五个号码中的占比不同
问题二
抽取随机来自两个专业五个人的学号

实验任务2

#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1
下一次循环时总价还包含上一次的价钱导致结果出错
问题2
跳过其之后的代码，再次回到选择饮料的环节即开始下一次循环

实验任务3

#include<stdio.h>

int main() {
    char m;
    while (scanf_s("%c", &m) !=EOF) {
        getchar();
        
        if (m == 'r') {
            printf("stop!\n");
        }
        else if (m == 'y') {
            printf("wait a minute\n");
        }
        else if (m == 'g') {
            printf("go go go\n");
        }
        else {
            printf("something must be wrong...\n");
        }
        
    }
    
    return 0;
}

s实验任务4

#include<stdio.h>

int main() {
    double m,s=0,max,min;
        scanf_s("%lf", &m);
        max = m;
        min = m;
        while (m != -1) {
            s += m;
        if (m > max) {
            max = m;
        }
        if (m < min) {
            min = m;
        }
        scanf_s("%lf", &m);
    }
        printf("今日累计消费总额%.1f\n",s);
        printf("今日最高一笔消费%.1f\n", max);
        printf("今日最低一笔消费%.1f\n", min);
    return 0;
}

实验任务5

#include<stdio.h>

int main() {
    int a, b, c;
    
    while (scanf_s("%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 == b == c) {
                printf("等边三角形\n");
            }
            else if (a != b && b != c&& a != c) {
                printf("普通三角形\n");
            }
            else {
                printf("等腰三角形\n");
            }
        }
    }
    return 0;
}

实验任务6

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main() {
    srand((unsigned int)time(NULL));
    int num = rand() % 30 + 1;
    int x;
    int m = 0;
    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(m<3){
        if (m != 0) {
            printf("再猜(1~30):");
        }
          scanf_s("%d", &x);
          m++;
            if (x == num) {
        printf("哇，猜中了:)");
        break;
            }
            else if (x <num) {
                printf("你猜的日期早了，你的lucky day还没到呢\n");
            }
            else if (x < num) {
                printf("你猜的日期晚了，你的lucky day在前面哦\n");
            }
            
             }
    if (m == 3 && x!= m) {
        printf("次数用光啦。偷偷告诉你，11月你的lucky day是%d号", num);
    }
        return 0;
}