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实验二 C语言分支与循环基础应用编程

news 2026/6/24 15:02:06

1.实验任务1

源代码

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <time.h>
 4 #define N 5
 5 int main() {
 6 int number;
 7 int i;
 8 srand(time(0)); 
 9 for(i = 0; i < N; ++i) {
10 number = rand() % 100 + 1;
11 printf("20490042%04d\n", number);
12 }
13 return 0;
14 }

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问题1 任意抽取5个学号

问题2 在1到100抽取一个随机数

问题3 占四个字符的位置，使格式更整齐

问题4 使每次生成的随机数都不一样

2.实验任务2

源代码

 1 #include <stdio.h>
 2 int main() {
 3 int choice, quantity;
 4 float total_price = 0, amount_paid, change;
 5 while (1) {
 6 printf("\n自动饮料售卖机菜单:\n");
 7 printf("1. 可乐 - 3 元/瓶\n");
 8 printf("2. 雪碧 - 3 元/瓶\n");
 9 printf("3. 橙汁 - 5 元/瓶\n");
10 printf("4. 矿泉水 - 2 元/瓶\n");
11 printf("0. 退出购买流程\n");
12 printf("请输入饮料编号: ");
13 scanf("%d", &choice);
14 if (choice == 0)
15 break;
16 if (choice < 1 || choice > 4) {
17 printf("无效的饮料编号，请重新输入。\n");
18 continue;
19 }
20 printf("请输入购买的数量: ");
21 scanf("%d", &quantity);
22 if (quantity < 0) {
23 printf("购买数量不能为负数，请重新输入。\n");
24 continue;
25 }
26 if(choice == 1 || choice == 2)
27 total_price += 3 * quantity;
28 else if(choice == 3)
29 total_price += 5 * quantity;
30 else
31 total_price += 2 * quantity;
32 printf("请投入金额: ");
33 scanf("%f", &amount_paid);
34 change = amount_paid - total_price;
35 printf("本次购买总价: %.2f 元\n", total_price);
36 printf("找零: %.2f 元\n", change);
37 total_price = 0;
38 }
39 printf("感谢您的购买，欢迎下次光临！\n");
40 return 0;
41 }

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问题1 如果去掉，第二次运行时totalprice的数值会在第一次的基础上累加

问题2 继续运行程序

3.实验任务3

源代码

 1 #include <stdio.h> 
 2 #include <stdlib.h>
 3 
 4 int main()
 5 {
 6     char c;
 7     while((c=getchar())!=EOF){
 8         if (c=='\n')continue;
 9         switch(c){
10             case'r':
11                 printf("stop!\n");
12                 break;
13             case'g':
14                 printf("go go go\n");
15                 break;
16             case'y':
17                 printf("wait a minute\n");
18                 break;
19             default:
20                 printf("something must be wrong...\n");
21                 break;
22         }
23     }
24     return 0;
25 }

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实验任务4

源代码

#include <stdio.h>int main() {double cost;double total = 0.0;double max_cost = 0.0;double min_cost = 20000.0; printf("输入今日开销，直到输入-1终止:\n");while (1) {scanf("%lf", &cost);if (cost == -1) {break;}total += cost;if (cost > max_cost) {max_cost = cost;}if (cost < min_cost) {min_cost = cost;}}printf("今日累计消费总额: %.1f\n", total);printf("今日最高一笔开销: %.1f\n", max_cost);printf("今日最低一笔开销: %.1f\n", min_cost);return 0;
}

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实验任务5

源代码

 1 #include <stdio.h>
 2 
 3 int main() {
 4     int a, b, c;
 5     while (scanf("%d %d %d", &a, &b, &c) != EOF) {
 6         if (a + b <= c || a + c <= b || b + c <= a) {
 7             printf("不能构成三角形\n");
 8             continue; 
 9         }
10         if (a == b && b == c) {
11             printf("等边三角形\n");
12         } else if (a == b || a == c || b == c) {
13             printf("等腰三角形\n");
14         } else if (a*a + b*b == c*c || a*a + c*c == b*b || b*b + c*c == a*a) {
15             printf("直角三角形\n");
16         } else {
17             printf("普通三角形\n");
18         }
19     }
20     return 0;
21 }

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实验任务6

源代码

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <time.h>
 4 
 5 int main() {
 6     int lucky_day, guess;
 7     int chance = 3;
 8 
 9         srand((unsigned int)time(NULL));
10         lucky_day = rand() % 30 + 1;
11 
12     printf("猜猜2026年4月哪一天是你的lucky day\n");
13     printf("开始喽，你有3次机会，猜吧(1~30)：");
14 
15     while (chance > 0) {
16         scanf("%d", &guess);
17 
18         if (guess == lucky_day) {
19             printf("哇，猜中了:)\n");
20             return 0;
21         } else if (guess > lucky_day) {
22             printf("你猜的日期晚了，你的lucky day在前面哦\n");
23         } else {
24             printf("你猜的日期早了，你的lucky day还没到呢\n");
25         }
26 
27         chance--;
28         if (chance > 0) {
29             printf("再猜(1~30)：");
30         }
31     }
32     printf("次数用光啦。4月你的lucky day是%d号\n", lucky_day);
33 
34     return 0;
35 }