Submission #183501

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Source Code Expand

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

int main(){
	ios_base::sync_with_stdio(false);
	int h, w;
	cin >> h >> w;
	vector< vector<int> > input(h, vector<int>(w));
	for(int i = 0; i < h; ++i){
		for(int j = 0; j < w; ++j){
			cin >> input[i][j];
			if((i + j) & 1){ input[i][j] *= -1; }
		}
	}
	vector< vector<int> > integral(h + 1, vector<int>(w + 1));
	for(int i = 0; i < h; ++i){
		int sum = 0;
		for(int j = 0; j < w; ++j){
			sum += input[i][j];
			integral[i + 1][j + 1] = integral[i][j + 1] + sum;
		}
	}
	int answer = 0;
	for(int y0 = 0; y0 < h; ++y0){
		for(int x0 = 0; x0 < w; ++x0){
			for(int y1 = y0 + 1; y1 <= h; ++y1){
				for(int x1 = x0 + 1; x1 <= w; ++x1){
					const int sum =
						  integral[y1][x1]
						+ integral[y0][x0]
						- integral[y1][x0]
						- integral[y0][x1];
					if(sum == 0){
						answer = max(answer, (y1 - y0) * (x1 - x0));
					}
				}
			}
		}
	}
	cout << answer << endl;
	return 0;
}

Submission Info

Judge Result