cf754 B. Ilya and tic-tac-toe game

呵呵呵，这个题简直是一直在乱做，真是最近太弱了

 #include<bits/stdc++.h>
 #define lowbit(x) x&(-x)
 #define LL long long
 #define N 200005
 #define M 1000005
 #define mod 2147483648LL
 #define inf 0x7ffffffff
 using namespace std;
 inline int ra()
 {
     int x=,f=; char ch=getchar();
     while (ch<'' || ch>''){if (ch=='-') f=-; ch=getchar();}
     while (ch>='' && ch<=''){x=x*+ch-''; ch=getchar();}
     return x*f;
 }
 int a[][];
 bool can(int x, int y)
 {
     if (x< || x>) return ;
     if (y< || y>) return ;
     return ;
 }
 bool check(int x, int y)
 {
     int tot=a[x][y];
     tot+=a[x-][y];
     tot+=a[x+][y];
     if (tot>=) return ; tot=a[x][y];
     tot+=a[x][y-];
     tot+=a[x][y+];
     if (tot>=) return ; tot=a[x][y];
     tot+=a[x-][y-];
     tot+=a[x+][y+];
     if (tot>=) return ; tot=a[x][y];
     tot+=a[x-][y+];
     tot+=a[x+][y-];
     if (tot>=) return ;
     return ;
 }
 int main()
 {
     for (int i=; i<=; i++)
         for (int j=; j<=; j++)
              a[i][j]=-;
     for (int i=; i<=; i++)
     {
         string ch; cin>>ch;
         for (int j=; j<=; j++)
         {
             if (ch[j-]=='x') a[i][j]=;
             if (ch[j-]=='.') a[i][j]=;
         }
     }
     for (int i=; i<=; i++)
         for (int j=; j<=; j++)
         {
             if ((a[i][j]== || a[i][j]==) && check(i,j))
             {
                 cout<<"YES";
                 return ;
             }
         }
     cout<<"NO";
     return ;
 }