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

// 判断是否为闰年
int runnian(int year) {
    return ((year % 4 == 0 && year % 100!= 0) || (year % 400 == 0));
}

// 计算某日期是周几（基姆拉尔森计算公式）
int howweek(int year, int month, int day) {
    if (month < 3) {
        month += 12;
        year--;
    }
    int week = (day + 2 * month + 3 * (month + 1) / 5 + year + year / 4 - year / 100 + year / 400) % 7;
    return week+1;
}

// 输出单个月份日历（单列输出）
void dl(int year, int month) {
    int dym;
     if (month == 2) {
       dym = runnian(year)? 29 : 28;
    } else if (month == 4 || month == 6 || month == 9 || month == 11) {
       dym = 30;
    } else {
        dym = 31;
    }

    int weekDay = howweek(year, month, 1);
	if(weekDay==7)
	weekDay=0;
    printf("     %d年%d月\n", year, month);
    printf(" 日 一 二 三 四 五 六\n");

    for (int i = 0; i < weekDay; i++) {
        printf("   ");
    }
    for (int i = 1; i <= dym; i++) {
        printf("%2d ", i);
        if ((i + weekDay) % 7 == 0) {
            printf("\n");
        }
    }
    printf("\n");
}
    
    // 输出整年日（单列输出）
void dl(int year) {
	if(year<=10000&&year>0){
    for (int month = 1; month <= 12; month++) {
       dl(year, month);
    }
}
else
printf("错误"); 
}

// 显示菜单
void cd() {
    printf("1. 查询日期是周几及是否闰年\n");
    printf("2. 输出单年日历（单列）\n");
    printf("3. 输出单年日历（双列）\n");
    printf("4. 退出\n");
    printf("请选择操作：");
}
int getValidIntInput() {
    int input;
    while (1) {
        if (scanf("%d", &input) == 1) {
            break;
        } else {
            printf("输入错误，请重新输入整数：");
            while (getchar()!= '\n');
        }
    }
    return input;
}

int main() {
    int choice;
    int year, month, day;

    do {
       cd();
        choice = getValidIntInput();

        switch (choice) {
        case 1:
            printf("请输入年份：");
            year = getValidIntInput();
            printf("请输入月份：");
            month = getValidIntInput();
            printf("请输入日期：");
            day = getValidIntInput();

            printf("%d年%d月%d日是星期", year, month, day);
            switch (howweek(year, month, day)) {
            case 0:
                printf("日");
                break;
            case 1:
                printf("一");
                break;
            case 2:
                printf("二");
                break;
            case 3:
                printf("三");
                break;
            case 4:
                printf("四");
                break;
            case 5:
                printf("五");
                break;
            case 6:
                printf("六");
                break;
            }
            printf("，");
            if (runnian(year)) {
                printf("该年是闰年\n");
            } else {
                printf("该年不是闰年\n");
            }
            break;
        case 2:
            printf("请输入年份：");
            year =getValidIntInput();
            dl(year);
            break;
        case 4:
            printf("退出程序\n");
            break;
        default:
            printf("无效的选择，请重新选择\n");
            break;
        }
    } while (choice!= 4);

    return 0;
}