实验二

1

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

#define N 5

 int main() {
    int number;
    int i;

     srand(time(0));
     for(i = 0; i < N; ++i) {
         number = rand() % 100 + 1;
         printf("20490042%04d\n", number);
    }
     system("pause");
     return 0;
 }

 

 1 生成1到100的随机数

2把number固定为至少四位，不够四位的前面用0补齐

3生成并打印五个学员编号

实验2

#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;
        }

        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");
    system("pause");
    return 0;
}

 

 

 1每次购买后重置数据，去掉的话会每次使用累加，导致结果出错

2break为终止，Continue为跳过

3没有必要，line17到18已经正确输入并做了检查

实验三

#include <stdio.h>

int main ()
{ char symbol;
while (scanf("%c",&symbol)!=EOF)
{getchar();
switch(symbol)
{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");
}
}
return 0;
}

 

 

 

实验4

#include <stdio.h>
#include <stdlib.h>
int main()
{double max = 0, min = 20000, exp, all_exp = 0;
printf("输入今日开销，直到输入-1终止：\n");

while (scanf("%lf",&exp), exp != -1)
{ if (exp<=0 ||exp >20000)
continue;
if (exp >= max)
max = exp;
if (exp <= min)
min = exp;
all_exp += exp;
}

printf("今日累计消费总额：%.1f\n", all_exp);

printf("今日最高一笔开销：%.1f\n", max );

printf("今日最低一笔开销：%.1f\n", min );

system("pause");
return 0;

 

 

实验5

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

int main() {
    // 使用当前时间作为随机数种子
    srand((unsigned int)time(NULL));
    // 生成[1, 30]之间的随机整数作为lucky day
    int luckyDay = rand() % 30 + 1;
    int guess;
    int attempts = 3;

    printf("猜猜2025年4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 (attempts > 0) {
        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;
}

 

 

 

实验6

#include <stdio.h>

void printRow(int n, int spaces) {
    for (int i = 0; i < spaces; i++) {
        printf("  "); 
    }
    for (int i = 0; i < n; i++) {
        printf("0   ");
    }
    printf("\n");

    for (int i = 0; i < spaces; i++) {
        printf("  ");
    }
    for (int i = 0; i < n; i++) {
        printf("<H> ");
    }
    printf("\n");

    for (int i = 0; i < spaces; i++) {
        printf("  ");
    }
    for (int i = 0; i < n; i++) {
        printf("I I ");
    }
    printf("\n");
}

int main() {
    int n;
    printf("请输入 n: ");
    scanf("%d", &n);

    printf("input n: %d\n", n);
    for (int i = n; i > 0; i--) {
        printRow(i, n - i);
    }
    return 0;
}