#include<stdio.h>

int isAvailable(int year);
void getDay(int year,int first_day[]);
int weak(int year);
void drawCalendar(int days[],int first_day[]);

int main(){
	int year=0;
	int days[12]={31,28.31,30,31,30,31,30,31,30,31,30};
	int first_day[12]={0};
	int i,t;
	
	for(t=1;t==1;){
		int n;
		printf("=============兴趣使然=============\n");
		printf("1.查询某年日历（单列输出）\n");
		printf("2,查询某年是什么年\n");
		printf("3.查询某年某月是星期几\n");
		printf("4.退出系统\n\n");
		
		
		printf("请输入选项下:");
		scanf("%d",&n);
		while(1){
		
			if(n==1){
				printf("请输入要查询的年份:");
				scanf("%d",&year);
			
				if(!isAvailable(year)){
					break;
				}
				
				getDay(year,first_day);
				
				if((year%4==0 && year%100!=0) || year%400==0){
					days[1]=29;
				}
				
				drawCalendar(days,first_day);
				putchar('\n');
				break;	
			}
			
			else if(n==2){
				printf("请输入要查询的年份:");
				scanf("%d",&year);
				
				if(!isAvailable(year)){
					break;
				}
				
				if((year%4==0 && year%100!=0) || year%400==0){
					printf("%d是闰年\n",year);
				}
				else{
					printf("%d是平年\n",year);
				}
				putchar('\n');
				break;		
			}
			else if(n==4){
				t=0;
				break;
			}
			else{
				printf("请输入要查询的年份:");
				scanf("%d",&year);
				if(!isAvailable(year)){
					break;
					
				}
				int weak1=0;
				weak1=weak(year);
				printf("星期%d",weak1);
				putchar('\n');
				break;
			}		
		}
	}
	return 0;
}

int isAvailable(int year){
	if(year>0){
		return 1;
	}
	return 0;
}
void getDay(int year,int first_day[]){
	int m=0;
	int d=1;
	int w=0;
	int y=year;
	for(m=3;m<=12;m++){
		w=(d + 1 + 2*m + 3*(m+1)/5 + y + y/4 - y/100 + y/400) % 7;
		first_day[m]=w;
	}
	y-=1;
	for(m=13;m<=14;m++){
		w=(d + 1 + 2*m + 3*(m+1)/5 + y + y/4 - y/100 + y/400) % 7;
		first_day[m-13]=w;
	}
}

void drawCalendar(int days[],int first_day[]){
	int space=0;
	int i=0,d=0,j=0;
	for(i=0;i<12;i++){
		space=first_day[i];
		
		printf("          %2d月日历\n",i+1);
		printf("|-----------------------------|\n");
		printf("|  日  一  二  三  四  五  六 |\n");
		printf("|-----------------------------|\n|");
		
		for(j=0;j<space;j++){
			printf("    ");
		}
		days[0]=31,days[2]=30,days[11]=30;
		for(d=1;d<=days[i];d++){
			printf("  %2d",d);
			if((d+space)%7==0){
				printf("|\n|");
			}
		}
		space=7-(d-1+space)%7;
		for(j=0;j<space;j++){
			printf("    ");
		}
		printf("|\n|----------------------------|\n|");
	}
	
}

int weak(int year){
	int d=0,k,j;
	k=year%100;
	j=year/100;
	int m=0;
	int w=0;
	int y=year;
	printf("请输入要查阅的月份及其日期:");
	scanf("%d%d",&m,&d);
	
	if(m<3){
		switch(m){
			case 1:m=13;break;
			case 2:m=14;break;
		}		
	}
	w=(d + 13 * (m + 1) / 5 + k + k / 4 + j / 4 + 5 * j)% 7;
	switch(w){
		case 0:w=6;break;
		case 1:w=7;break;
		case 2:w=1;break;
		case 3:w=2;break;
		case 4:w=3;break;
		case 5:w=4;break;
		case 6:w=5;break;
	}
	return w;
}