Submission #4043432

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define repi(i,a,b) for(int i=int(a);i<(int)(b);i++)
#define reps(i,n) for(int i=0;i<=(int)(n);i++)
#define all(x) (x).begin(),(x).end()
#define foreach(u,v) for(auto (u) : (v))
#define pb push_back
#define mp make_pair
#define mt make_tuple

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<ll, ll> pll;
typedef vector<ll> vl;

const int inf = 1e9;
const ll linf = 1e18;
const ll mod = 1e9 + 7;
const double eps = 1e-9;

int main()
{
  int h, w; 
  cin >> h >> w;

  vvi c(h+1, vi(w+1));
  repi(i, 1, h+1) repi(j, 1, w+1) cin >> c[i][j];

  vector<vvi> s(2, vvi(h+1, vi(w+1)));
  rep(k, 2) repi(i, 1, h+1) repi(j, 1, w+1){
    s[k][i][j] = s[k][i][j-1];
    if(k == (i+j)%2) s[k][i][j] += c[i][j];
  }

  rep(k, 2) repi(i, 1, h+1) repi(j, 1, w+1){
    s[k][i][j] += s[k][i-1][j];
  }

  int ans = 0;
  repi(x1, 1, w+1) repi(y1, 1, h+1){
    repi(x2, x1, w+1) repi(y2, y1, h+1){
      int b = s[0][y2][x2]-s[0][y2][x1-1]-s[0][y1-1][x2]+s[0][y1-1][x1-1];
      int w = s[1][y2][x2]-s[1][y2][x1-1]-s[1][y1-1][x2]+s[1][y1-1][x1-1];
      if(b == w){
//        printf("%d,%d,%d,%d\n", x1, y1, x2, y2);
        int area = (x2-x1+1)*(y2-y1+1);
        ans = max(ans, area);
      }
    }
  }
  
  cout << ans << endl;

  return 0;
}

Submission Info

Judge Result