实验2

实验1.

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define N 5

int main() {
    int number;
    int i;

    srand(time(0));     // 以当前系统时间作为随机种子
    for (i = 0; i < N; ++i) {
        number = rand() % 100 + 1;
        printf("20490042%04d\n", number);
    }

    return 0;
}

 

1.生成一个随机数

2.使符号宽度为4，如果不够的话就在前面用0补上

3.输出5个特定格式的编号，20490042****

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;
        }

        switch (choice) {
            case 1:
            case 2:
                total_price += 3 * quantity;
                break;
            case 3:
                total_price += 5 * quantity;
                break;
            case 4:
                total_price += 2 * quantity;
                break;
        }

        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;
}

　　

 

1.将总价格重置为0，下一次循环total_price为0

2.break终止while(0)这个无限循环，cntinue跳过后续操作回到循环开头

3.有

实验3

#include <stdio.h>

int main() {
    char input;
    while (scanf_s("%c", &input,1) != EOF) {
        getchar();  // 读取并丢弃换行符
        switch (input) {
        case 'r':
            printf("stop!\n");
            break;
        case 'g':
            printf("go go go\n");
            break;
        case 'y':
            printf("wait a minute\n");
            break;
        default:
            printf("something must be wrong...\n");
            break;
        }
    }
    return 0;
}

4.实验4

#include <stdio.h>

int main() {
    double expense, total = 0, max = 0, min = 20000;
    // total 记录总开销，max 记录最高开销，min 记录最低开销，初始设min为20000
    printf("输入今日开销，直到输入-1终止:\n");
    while (1) {
        scanf("%lf", &expense);
        if (expense == -1) {
            break;
        }
        total += expense;
        if (expense > max) {
            max = expense;
        }
        if (expense < min) {
            min = expense;
        }
    }
    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;
}

5.实验5

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main() {
    int luckyDay, guess, attempts = 3;
    srand(time(0));
    luckyDay = rand() % 30 + 1;  // 生成1到30之间的随机整数

    printf("猜猜2025年4月哪一天是你的lucky day\n");
    while (attempts > 0) {
        printf("开始喽，你有三次机会，猜吧(1~30): ");
        scanf("%d", &guess);

        if (guess == luckyDay) {
            printf("哇，猜中了:)\n");
            break;
        }
        else if (guess < luckyDay) {
            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");
        }

        attempts--;
        if (attempts > 0) {
            printf("再猜(1~30): ");
        }
    }

    if (attempts == 0) {
        printf("次数用完啦，偷偷告诉你，4月你的lucky day是%d号\n", luckyDay);
    }

    return 0;
}

6.实验6

#include <stdio.h>

int main() {
    int n, i, j, k;
    printf("input n: ");
    scanf("%d", &n);

    for (i = n; i >= 1; i--) {
        // 打印每行前面的空格
        for (j = 0; j < n - i; j++) {
            printf("   ");
        }
        // 打印小人头部和身体上半部分
        for (k = 0; k < 2 * i - 1; k++) {
            printf(" 0 ");
            if (k != 2 * i - 2) {
                printf(" ");
            }
        }
        printf("\n");
        for (j = 0; j < n - i; j++) {
            printf("   ");
        }
        for (k = 0; k < 2 * i - 1; k++) {
            printf("<H>");
            if (k != 2 * i - 2) {
                printf(" ");
            }
        }
        printf("\n");
        for (j = 0; j < n - i; j++) {
            printf("   ");
        }
        for (k = 0; k < 2 * i - 1; k++) {
            printf(" I ");
            if (k != 2 * i - 2) {
                printf(" ");
            }
        }
        printf("\n");
    }

    return 0;
}