Submission #470358

#	Time	Username	Problem	Language	Result	Execution time	Memory
470358		tutis	Rectangles (IOI19_rect)	C++17	0 / 100	2511 ms	196072 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
using namespace std;
long long count_rectangles(vector<vector<int> > a) {
	int n = a.size();
	int m = a[0].size();
	vector<vector<int>> j2(n, vector<int>(m, -1));
	vector<vector<int>> j1(n, vector<int>(m, -1));
	vector<vector<int>> i2(n, vector<int>(m, -1));
	vector<vector<int>> i1(n, vector<int>(m, -1));
	for (int i = 0; i < n; i++)
	{
		vector<int>A;
		for (int j = 0; j < m; j++)
		{
			while (A.size() > 0 && a[i][A.back()] <= a[i][j])
				A.pop_back();
			if (!A.empty())
				if (A.back() + 1 <= j - 1)
					j1[i][j] = A.back();
			A.push_back(j);
		}
		A.clear();
		for (int j = m - 1; j >= 0; j--)
		{
			while (A.size() > 0 && a[i][A.back()] < a[i][j])
				A.pop_back();
			if (!A.empty())
				if (j + 1 <= A.back() - 1)
					j2[i][j] = A.back();
			A.push_back(j);
		}
	}
	for (int j = 0; j < m; j++)
	{
		vector<int>A;
		for (int i = 0; i < n; i++)
		{
			while (A.size() > 0 && a[A.back()][j] <= a[i][j])
				A.pop_back();
			if (!A.empty())
			{
				if (A.back() + 1 <= i - 1)
					i1[i][j] = A.back();
				else
					i1[i][j] = -1;
			}
			else
				i1[i][j] = -1;
			A.push_back(i);
		}
		A.clear();
		for (int i = n - 1; i >= 0; i--)
		{
			while (A.size() > 0 && a[A.back()][j] < a[i][j])
				A.pop_back();
			if (!A.empty())
			{
				if (i + 1 <= A.back() - 1)
					i2[i][j] = A.back();
				else
					i2[i][j] = -1;
			}
			else
				i2[i][j] = -1;
			A.push_back(i);
		}
	}
	long long ans = 0;
	set<tuple<int, int, int, int>>S;
	auto check = [&](int x1, int x2, int y1, int y2)->void
	{
		if (x1 == -1 || x2 == -1 || y1 == -1 || y2 == -1)
			return;
		if (S.count({x1, x2, y1, y2}))
		return;
		S.insert({x1, x2, y1, y2});
		for (int i = x1 + 1; i < x2; i++)
		{
			if (j2[i][y1] != y2 && j1[i][y2] != y1)
				return;
		}
		for (int j = y1 + 1; j < y2; j++)
		{
			if (i2[x1][j] != x2 && i1[x2][j] != x1)
				return;
		}
		ans++;
	};
	for (int x1 = 0; x1 < n; x1++)
		for (int x2 = x1 + 2; x2 < n; x2++)
		{
			for (int y1 = 0; y1 < m; y1++)
				for (int y2 = y1 + 2; y2 < m; y2++)
				{
					check(x1, x2, y1, y2);
				}
		}
	// for (int i = 0; i < n; i++)
	// {
	// 	for (int j = 0; j < m; j++)
	// 	{
	// 		if (j != 0 && j != m - 1)
	// 			for (int i_ : {i1[i][j], i2[i][j]})
	// 			{
	// 				if (i_ == -1)
	// 					continue;
	// 				int x1 = i;
	// 				int x2 = i_;
	// 				if (x1 > x2)
	// 					swap(x1, x2);
	// 				check(x1, x2, j - 1, j2[x1 + 1][j - 1]);
	// 				check(x1, x2, j - 1, j2[x2 - 1][j - 1]);
	// 				check(x1, x2, j1[x1 + 1][j + 1], j + 1);
	// 				check(x1, x2, j1[x2 - 1][j + 1], j + 1);
	// 			}
	// 	}
	// }
	return ans;
}
// int main()
// {
// 	cout << count_rectangles({{1, 1, 1}, {1, 0, 1}, {1, 1, 1}}) << endl;
// }

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