百练 2723 不吉利日期

题目链接：http://bailian.openjudge.cn/practice/2723

#include<stdio.h>int main(){int day[13]={0,12,31,28,31,30,31,30,31,31,30,31,30};int w;int i;scanf("%d",&w);for(i=1;i<=12;i++){w=(w+day[i])%7;if(w==5) printf("%d\n",i);}return 0;}