实验二

1.实验任务一
问题一：打印5个1到100的随机整数
问题二：生成一个1到100之间的整数
问题三：控制位数
问题四：去掉生成的数固定的。使生成的数字随机

2.实验任务二
问题一：去掉之后总价不会清零，会不断叠加
问题二：continue是结束当前一次循环。都是回到while（1）开头

3.实验任务三
`#define _CRT_SECURE_NO_WARNINGS 1

include <stdio.h>

int main() {
char c;
while (scanf("%c", &c) != EOF) {

    getchar();

    if (c == 'r') {
        printf("stop!\n");
    }
    else if (c == 'g') {
        printf("go go go\n");
    }
    else if (c == 'y') {
        printf("wait a minute\n");
    }
    else {
        printf("something must be wrong...\n");
    }
}
return 0;

}`

实验任务四：
`#define _CRT_SECURE_NO_WARNINGS 1

include <stdio.h>

int main() {
double expense, total = 0;
double max_e = 0, min_e = 20000;
int count = 0;

printf("输入今日开销，直到输入-1终止:\n");

while (1) {
    scanf("%lf", &expense);
    if (expense == -1)
        break;
    if (expense <= 0 || expense > 20000) {
        printf("输入无效！\n");
        continue;
    }
    total += expense;
    count++;
    if (expense > max_e)
        max_e = expense;
    if (expense < min_e)
        min_e = expense;
}

if (count == 0) {
    printf("未输入任何有效开销！\n");
    return 0;
}

printf("\n今日最高一笔开销：%.1f 元\n", max_e);
printf("今日最低一笔开销：%.1f 元\n", min_e);
printf("今日累计消费总额：%.1f 元\n", total);

return 0;

}`

实验任务五：
`#define _CRT_SECURE_NO_WARNINGS 1

include <stdio.h>

int main() {
int a, b, c, t;
while (scanf("%d %d %d", &a, &b, &c) != EOF) {
if (a <= 0 || b <= 0 || c <= 0) {
printf("不能构成三角形\n");
continue;
}

    if (a > b) { t = a; a = b; b = t; }
    if (a > c) { t = a; a = c; c = t; }
    if (b > c) { t = b; b = c; c = t; }

    if (a + b <= c) {
        printf("不能构成三角形\n");
        continue;
    }

    if (a == b && b == c) {
        printf("等边三角形\n");
    } else if (a == b || b == c) {
        if (a * a + b * b == c * c)
            printf("等腰直角三角形\n");
        else
            printf("等腰三角形\n");
    } else if (a * a + b * b == c * c) {
        printf("直角三角形\n");
    } else {
        printf("普通三角形\n");
    }
}
return 0;

}`

实验任务六：

define _CRT_SECURE_NO_WARNINGS 1

include <stdio.h>

include <stdlib.h>

include <time.h>

int main() {
int lucky, guess, i;
srand((unsigned int)time(NULL));
lucky = rand() % 30 + 1;

printf("猜猜2026年4月哪一天是你的lucky day\n");

for (i = 0; i < 3; i++) {
    if (i == 0)
        printf("开始喽，你有3次机会，猜吧(1~30)：");
    else
        printf("再猜(1~30)：");

    scanf("%d", &guess);

    if (guess == lucky) {
        printf("你猜中了\n");
        return 0;
    }
    else if (guess > lucky) {
        printf("你猜的日期晚了，你的lucky day在前面哦\n");
    }
    else {
        printf("你猜的日期早了，你的lucky day还没到呢\n");
    }
}

printf("你用光了3次机会，你在4月的lucky day是：%d\n", lucky);
return 0;

}