南阳理工OJ 219 An problem about date 给日期求星期

#include<stdio.h>
int month[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int year[9604];
bool is_leay(int i)
{
    return i%400==0||i%4==0&&i%100;
}
int main()
{
    int i;
    for(i=1;i<=12;i++)month[i]+=month[i-1];
    for(i=1600;i<=9600;i++)
        if(is_leay(i))year[i]=year[i-1]+366;
        else year[i]=year[i-1]+365;
    int y,m,d,n;
    while(~scanf("%d%d%d",&y,&m,&d))
    {
        n=0;
        n+=year[y-1]+month[m-1]+d;
        if(is_leay(y)&&m>2)n+=1;
        printf("%d\n",(n+5)%7);
    }
    return 0;
}

 

 

#include<stdio.h>
int main()
{
	int y,m,d,c,w,t;
	while(scanf("%d%d%d",&y,&m,&d)!=EOF)
	{
	    if(m<=2){m+=12;y--;}
	    c=y/100;
	    y=y%100;
	    w=((y+(y>>2)+(c>>2)-(c<<1)+(26*(m+1)/10)+d-1)%7+7)%7;
	   printf("%d\n",w);
	}
	return 0;
}