제출 #830184

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
830184		GusterGoose27	Rectangles (IOI19_rect)	C++17	10 / 100	4 ms	1292 KiB

rect

#include "rect.h"

#include <bits/stdc++.h>

using namespace std;

const int MAXN = 2505;
const int inf = 1e9;

typedef pair<int, int> pii;
typedef pair<pii, pii> rect;

set<rect> cands;
int prv[2][MAXN][MAXN];
int nxt[2][MAXN][MAXN];
int n, m;

void make(int store[][MAXN], bool rc, bool dir, vector<vector<int>> &a, int v) {
	vector<pii> stck;
	stck.push_back(pii(inf, -1));
	int sz = (rc ? n : m);
	for (int i = (dir ? sz-1 : 0); (dir ? i >= 0 : i < sz); (dir ? i-- : i++)) {
		int cur = (rc) ? a[i][v] : a[v][i];
		while (cur >= stck.back().first) stck.pop_back();
		if (rc) store[i][v] = stck.back().second;
		else store[v][i] = stck.back().second;
		stck.push_back(pii(cur, i));
	}
}

map<pii, vector<int>> occ[2]; // row, then column

int cnt_leq(vector<int> &v, int i) {
	int mn = -1;
	int mx = v.size();
	while (mx > mn+1) {
		int cur = (mn+mx)/2;
		if (v[cur] <= i) mn = cur;
		else mx = cur;
	}
	return mx;
}

void print(rect &r) {
	cout << r.first.first << ' ' << r.first.second << ' ' << r.second.first << ' ' << r.second.second << '\n';
}

long long count_rectangles(vector<vector<int>> a) {
	n = a.size();
	m = a[0].size();
	for (int i = 0; i < n; i++) {
		make(prv[0], 0, 0, a, i);
		make(nxt[0], 0, 1, a, i);
	}
	for (int i = 0; i < m; i++) {
		make(prv[1], 1, 0, a, i);
		make(nxt[1], 1, 1, a, i);
	}
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			int suc = 0;
			for (int t = 0; t < 2; t++) {
				int rcpos = (t ? i : j);
				if (nxt[t][i][j] != -1 && prv[t][i][j] != -1) {
					suc++;
					if (nxt[t][i][j]) {
						occ[t][pii(prv[t][i][j]+1, nxt[t][i][j]-1)].push_back(i^j^rcpos);
					}
				}
			}
			if (suc == 2) {
				// cerr << i << ' ' << j << '\n';
				cands.insert(rect(pii(prv[1][i][j]+1, prv[0][i][j]+1), pii(nxt[1][i][j]-1, nxt[0][i][j]-1)));
			}
		}
	}
	for (auto &it: occ[0]) {
		sort(it.second.begin(), it.second.end());
	}
	for (auto &it: occ[1]) {
		sort(it.second.begin(), it.second.end());
	}
	int ans = 0;
	// cerr << cands.size() << '\n';
	for (rect r: cands) {
		pii up = r.first;
		pii down = r.second;
		pii xrange = pii(up.first, down.first);
		pii yrange = pii(up.second, down.second);
		if (cnt_leq(occ[0][yrange], xrange.second)-cnt_leq(occ[0][yrange], xrange.first-1) == xrange.second-xrange.first+1
			&& cnt_leq(occ[1][xrange], yrange.second)-cnt_leq(occ[1][xrange], yrange.first-1) == yrange.second-yrange.first+1) {

			// print(r);
			ans++;
		}

	}
	return ans;
}

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