hdu2133: http://acm.hdu.edu.cn/showproblem.php?pid=2133
题意（解法）：已知0年1月1日是周6，输入一个日期，问星期几
code：
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
int tianshu1[]={31,28,31,30,31,30,31,31,30,31,30,31};
int tianshu2[]={31,29,31,30,31,30,31,31,30,31,30,31};
char tab[7][10]={"Saturday","Sunday","Monday","Tuesday","Wednesday","Thursday","Friday"};
bool runnian(int n)
{
if((n%4==0&&n%100!=0)||n%400==0)
return true;
else
return false;
}
int main()
{
int y,m,d;
while(scanf("%d%d%d",&y,&m,&d)!=EOF)
{
int ans=0;
if(m==0||d==0||(!runnian(y)&&d>tianshu1[m-1])||(runnian(y)&&d>tianshu2[m-1]))
{
printf("illegal\n");
continue;
}
for(int i=0;i<y;i++)
{
if(runnian(i))
ans=ans+366;
else
ans=ans+365;
}
for(int i=1;i<m;i++)
{
if(runnian(y))
ans=ans+tianshu2[i-1];
else
ans=ans+tianshu1[i-1];
}
ans=ans+d-1;
printf("%s\n",tab[ans%7]);
}
}
/*input:
2007 11 17
output:
Saturday*/
