实验2 C语言分支与循环基础应用编程

实验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));
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;
}

作用：将时间作为随机数种子，每次生成不同随机数

去掉后只能生成一组随机数

功能：随机生成学号

 

实验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;
}

去掉后每次运行的总金额会进行叠加

不进行剩下的 直接进行下一次循环

 

实验3

#include <stdio.h>
int main() {
    char x;
    printf("请输入交通信号灯颜色：");
    while(1){
        scanf(" %c", &x);
        if(x == 'q' || x == 'Q'){
            break;
        }
        if(x == 'r' || x == 'R'){
            printf("stop!\n");
        }
        else if(x == 'g' || x == 'G'){
            printf("go go go\n");
        }
        else if(x == 'y' || x == 'Y'){
            printf("wait a minute\n");
        }
        else{
            printf("something must be wrong...\n");
            
        }
        printf("请输入交通信号灯颜色："); 
    } 

return 0;
}

 

实验4

#include <stdio.h>
int main() {
    float money;
    float total = 0;
    float max = 0;
    float min = 0;
    int first = 1;
    
    printf("输入今日开销，直到输入-1终止：\n");
    
    while (1) {
        scanf("%f", &money);
        
        if (money == -1) {
            break;
        }
        
        if (first == 1) {
            min = money;
            first = 0;
        }
        
        total = total + money;
        
        if (money > max) {
            max = money;
        }
        
        if (money < min) {
            min = money;
        }
    }
    
    printf("今日累计消费总额：%.1f\n", total);
    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5

#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) {
            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 (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");
            }
        } else {
            printf("不能构成三角形\n");
        }
    }
    
    return 0;
}

 

实验6

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