算法提高 日期计算

#include<cstdio>
#include<cstdlib>
#include<cstring>
using namespace std;
int week[3005][15][35];
int month1[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int month2[13]={0,31,29,31,30,31,30,31,31,30,31,30,31};
void count(){
	int year=2011,month=11,day=11,ans=5;
	week[year][month][day]=5;
	while(1){
		if(year==3000)break;
		if(year%400==0||(year%4==0&&year%100!=0)){
			day++;if(day>month2[month]){month++;day=1;}
			if(month>12){month=1;year++;}
			ans++;if(ans>7)ans=1;
			week[year][month][day]=ans;
		}
		else {
			day++;if(day>month1[month]){month++;day=1;}
			if(month>12){month=1;year++;}
			ans++;if(ans>7)ans=1;
			week[year][month][day]=ans;
		}
	}
	year=2011;month=11;day=11;ans=5;
	while(1){
		if(year==1598)break;
		if(year%400==0||(year%4==0&&year%100!=0)){
			day--;
			if(day<=0){
				month--;
				if(month<=0)day=31;
				else day=month2[month];
			}
			if(month<=0){month=12;year--;}
			ans--;if(ans<=0)ans=7;
			week[year][month][day]=ans;
		}
		else {
			day--;
			if(day<=0){
				month--;
				if(month<=0)day=31;
				else day=month1[month];
			}
			if(month<=0){month=12;year--;}
			ans--;if(ans<=0)ans=7;
			week[year][month][day]=ans;
		}
	}
}
int main()
{
	count();
	int y,m,d;
	while(~scanf("%d%d%d",&y,&m,&d))
	printf("%d\n",week[y][m][d]);
	return 0;
}