Friday the Thirteenth

USACO成长笔记，不急，慢慢来嘛

/*ID: 13913351LANG: CPROG: friday*/#include<stdio.h>#include<string.h>int week[7];int main(){    FILE *fin  = fopen ("friday.in", "r");    FILE *fout = fopen ("friday.out", "w");    memset(week,0,sizeof(week));    int N;    int y,m,d;//年 月 日     int w;//星期     int i,j;    fscanf(fin,"%d",&N);    d=13;     for(i=1900;i<=1900+N-1;i++)    {        int y=i;        for(j=1;j<=12;j++)        {            int m=j;            if(m==1||m==2)            {                m+=12;                y--;            }            w=(y+y/4+y/400-y/100+2*m+3*(m+1)/5+d)%7; //此蔡勒公式公式在1752年9月3日后成立             week[w]++;  //week[i]表示 星期 i+1;            if(m>12)y++;//一月，二月计算过后表年份的y减1，在后续计算需要恢复         }    }    fprintf(fout,"%d %d ",week[5],week[6]);          for(i=0;i<4;i++)    {        fprintf(fout,"%d ",week[i]);    }     fprintf(fout,"%d\n",week[4]);    return 0; }