编辑代码

#include <stdio.h>

int main() {
    int num;
    while (1) {
        printf("请输入 0 - 7 的数字（输入 0 退出）：");
        if (scanf("%d", &num) != 1) {
            printf("输入无效，请输入一个有效的整数。\n");
            // 清除输入缓冲区
            while (getchar() != '\n');
            continue;
        }

        switch (num) {
            case 0:
                printf("退出程序。\n");
                break;
            case 1:
                printf("Monday\n");
                break;
            case 2:
                printf("Tuesday\n");
                break;
            case 3:
                printf("Wednesday\n");
                break;
            case 4:
                printf("Thursday\n");
                break;
            case 5:
                printf("Friday\n");
                break;
            case 6:
                printf("Saturday\n");
                break;
            case 7:
                printf("Sunday\n");
                break;
            default:
                printf("输入的数字不在 0 - 7 范围内，请重新输入。\n");
                continue;
        }

        if (num == 0) {
            break;
        }
    }

    return 0;
}