1 /*
2 1600年一月一日为星期6，所以算出ymd与1600-1-1差多少天对7取余即可
3 */
4 #include<stdio.h>
5 int a[10000]={0};
6 int main()
7 {
8 int i,y,m,d,t = 0,ans;
9 for(i=1600; i<9601; i+=4)
10 {
11 if(i%100 != 0 || i%400==0)
12 ++t;
13 a[i-1599] = a[i-1598] = a[i-1597] = a[i-1596] = t;
14 }
15 while(~scanf("%d%d%d",&y,&m,&d))
16 {
17 ans = 5 + (y-1600)*365 + a[y-1600];
18 switch(m)
19 {
20 case 2:d+=31;break;
21 case 3:d+=59;break;
22 case 4:d+=90;break;
23 case 5:d+=120;break;
24 case 6:d+=151;break;
25 case 7:d+=181;break;
26 case 8:d+=212;break;
27 case 9:d+=243;break;
28 case 10:d+=273;break;
29 case 11:d+=304;break;
30 case 12:d+=334;break;
31 }
32 if( (m>2 && y%4==0 && y%100!=0) || y%400==0 && m>2)
33 d++;
34 ans += d;
35 printf("%d\n",ans%7);
36 }
37 return 0;
38 }
1 //最优解
2 #include<cstdio>
3 int main()
4 {
5 int y,m,d;
6 while(~scanf("%d%d%d",&y,&m,&d))
7 {
8 if(m<3) m+=12,--y;
9 printf("%d\n",(d+2*m+3*(m+1)/5+y+y/4-y/100+y/400+1)%7); //蔡勒公式的变种
10 }
11 }
