Submission #2408242

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Source Code Expand

#include <bits/stdc++.h>
#define range(i, a, b) for(int i = (a); i < (b); i++)
#define rep(i, a) range(i, 0, a)
using namespace std;

int h, w, black[110][110], white[110][110];

#include <boost/numeric/ublas/matrix.hpp>
using boost::numeric::ublas::matrix;
template <typename T>
class CumulativeSum2D {
	public:
	matrix<T> sum;
	CumulativeSum2D (int h, int w) {
		sum = matrix<T>(h + 1, w + 1);
	}

	void add(int x, int y, T num) {
		x++;
		y++;
		sum(x, y) += num;
	}

	void build() {
		for (int i = 1; i < sum.size1(); i++) {
			for (int j = 1; j < sum.size2(); j++) {
				sum(i, j) += sum(i, j - 1) + sum(i - 1, j) - sum(i - 1, j - 1);
			}
		}
	}

	T query(int sx, int sy, int gx, int gy) {
		return (sum(gx, gy) - sum(sx, gy) - sum(gx, sy) + sum(sx, sy));
	}
};

int main() {
	cin >> h >> w;
	CumulativeSum2D<int> white(h, w), black(h, w);
	rep (i, h) rep (j, w) {
		int in;
		cin >> in;
		(i + j) % 2 ? white.add(i, j, in) : black.add(i, j, in);
	}
	white.build();
	black.build();
	int ans = 0;
	rep (i, h) rep (j, w) range (k, i + 1, h + 1) range (l, j + 1, w + 1) {
		if (white.query(i, j, k, l) == black.query(i, j, k, l))
			ans = max(ans, (k - i) * (l - j));
	}
	cout << ans << endl;
	return 0;
}

Submission Info

Judge Result