URAL 2048 Histroy

#include<cstdio>
#include<cstring>

bool isLeapYear(int y)
{
   if(y%100){
      return !(y&3);
   }
   else {
      return !(y%400);
   }
}
               // 1    3     5     7   8    10    12
int days[] = {-1,31,28,31,30,31,30,31,31,30,31,30,31};
//6 7 1 2 3 4 5
int cnt1[7];//1~2月
int cnt2[7];//2月以后
int cnt[7];

//1900
void firstYear()
{
   int v = 0;
  for(int m = 1; m <= 2; m++) {
      cnt1[v]++;
      v = (v+days[m])%7;
  }
  for(int m = 3; m <= 12; m++) {
      cnt2[v]++;
      v = (v+days[m])%7;
  }
  for(int i = 0; i < 7; i++) {
      cnt[i] = cnt1[i]+cnt2[i];
  }
}

int cnt400[401][13];
int cntCur[7];

void circle()
{
   firstYear();
   int mov = 0;
   int i = 1;//1900
   for(int y = 1900; y < 2300; y++,i++){//1,1 +mov1 1,2 2->last 1
      memset(cntCur,0,sizeof(cntCur));
      if(isLeapYear(y)) {
         for(int i = 0; i < 7; i++)//2月以前不受影响
            cntCur[i] += cnt1[(i-mov+7)%7];
         mov = (mov + 1)%7;//相对上一年
         for(int i = 0; i < 7; i++)
            cntCur[i] += cnt2[(i-mov+7)%7];

      }
      else {
         for(int i = 0; i < 7; i++)
            cntCur[i] += cnt[(i-mov+7)%7];
      }
      mov = (mov + 1)%7;//365%7 =1
      for(int j = 0; j < 13; j++){
        cnt400[i][j] = cnt400[i-1][j];
      }
      cnt400[i][cntCur[6]]++;
   }
}


int ans[13];
//#define local
int main()
{
#ifdef local
    freopen("data.txt","w",stdout);
#endif // local
   int A,B;
   circle();
   scanf("%d%d",&A,&B);
        B++;A++;
        int a = (A-1-1900)%400;
        int na = (A-1-1900)/400;
        int b = (B-1900)%400;
        int nb = (B-1900)/400;
        for(int i = 0; i < 13; i++){
            ans[i] += (nb-na)*cnt400[400][i] + cnt400[b][i] - cnt400[a][i];
        }
    for(int i = 0; i < 13; i++)
      printf("%d: %d\n",i,ans[i]);

    return 0;
}