Submission #2006565

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Source Code Expand

#include <bits/stdc++.h>
#include <vector>
#define REP(i,n) for(int i=0;i<n;i++)
using namespace std;
typedef long long ll;

int h,w;


int main(){
  cin>>h>>w;
  int c[h][w];

  REP(i,h){
    REP(j,w){
      int k;
      cin>>k;
      if((i+j)%2==0){
        c[i][j] = k;
      }else{
        c[i][j] = -k;
      }
    }
  }
  
  int hs[h][w];
  hs[0][0] = c[0][0];
  for(int i=1;i<h;i++){
    hs[i][0] = hs[i-1][0] + c[i][0];
  }
  for(int i=1;i<w;i++){
    hs[0][i] = hs[0][i-1] + c[0][i];
  }
  for(int i=1;i<h;i++){
    for(int j=1;j<w;j++){
      hs[i][j] = hs[i-1][j] + hs[i][j-1] - hs[i-1][j-1] + c[i][j];
    }
  }
  

  
  int ans =0;
  REP(i,h){
    REP(j,w){
      for(int k=i;k<h;k++){
        for(int l=j;l<w;l++){
          int chokoSum;
          if(i==0&&j==0){
            chokoSum = hs[i][j];
          }else if(i==0){
            chokoSum = hs[k][l] - hs[i][j-1];
          }else if(j==0){
            chokoSum = hs[k][l] - hs[i-1][j];
          }else{
            chokoSum = hs[k][l] - hs[k][j-1] - hs[i-1][l] + hs[i-1][j-1];
          }
          if(chokoSum == 0){
            ans = max(ans,(k-i+1)*(l-j+1));
          }
        }
      }
    }
  }
  cout<<ans<<endl;
}

Submission Info

Judge Result