Submission #415791

#	Time	Username	Problem	Language	Result	Execution time	Memory
415791		Mlxa	Rectangles (IOI19_rect)	C++14	13 / 100	613 ms	441916 KiB

rect

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) x.begin(), x.end()
#define mp make_pair
#define mt make_tuple
#define x first
#define y second
#include "rect.h"

namespace my {
const int N = 2520;
const int INF = N;

int n, m;
int a[N][N];
bool used[N][N];

int cnt = 0;
int li, lj, ri, rj;
bool bad;

void dfs(int i, int j) {
	if ((i == 0 || j == 0 || i == n - 1 || j == m - 1) && !a[i][j]) {
		bad = true;
		return;
	}
	if (used[i][j] || a[i][j] || i < 1 || i > n - 2 || j < 1 || j > m - 2) {
		return;
	}
	used[i][j] = true;
	li = min(li, i); ri = max(ri, i);
	lj = min(lj, j); rj = max(rj, j);
	++cnt;
	dfs(i - 1, j);
	dfs(i + 1, j);
	dfs(i, j - 1);
	dfs(i, j + 1);
}

}

ll count_rectangles(vector<vector<int>> _a) {
	using namespace my;
	n = (int)_a.size(), m = (int)_a[0].size();
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < m; ++j) {
			a[i][j] = _a[i][j];
		}
	}
	int answer = 0;
	for (int i = 1; i < n - 1; ++i) {
		for (int j = 1; j < m - 1; ++j) {
			if (used[i][j] || a[i][j]) {
				continue;
			}
			cnt = 0;
			bad = false;
			li = INF, lj = INF, ri = -INF, rj = -INF;
			dfs(i, j);
			if (!bad && cnt == (ri - li + 1) * (rj - lj + 1)) {
				++answer;
			}
		}
	}
	return answer;
}

#ifdef LC
#include "grader.cpp"
#endif

• Subtask 1: 0 / 8
• Subtask 2: 0 / 7
• Subtask 3: 0 / 12
• Subtask 4: 0 / 22
• Subtask 5: 0 / 10
• Subtask 6: 13 / 13
• Subtask 7: 0 / 28