제출 #822982

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
822982		vjudge1	Rectangles (IOI19_rect)	C++17	10 / 100	3 ms	612 KiB

rect

#include<bits/stdc++.h>
#include "rect.h"

using namespace std;
using ll = long long;

// O(nlogn)
set<pair<int, int>> get_segments(vector<int> &a) {
	vector<pair<int, int>> b;
	set<pair<int, int>> res;
	int n = (int)a.size();
	for(int i = 0; i < n; i++) {
		b.push_back({a[i], i});
	}
	sort(b.rbegin(), b.rend());
	set<int> st;
	for(auto [x, pos] : b) {
		st.insert(pos);
		auto it = st.lower_bound(pos);
		if(it != st.begin()) {
			auto lb = it; lb--;
			if(*it - *lb > 1) 
				res.insert({*lb + 1, *it - 1});
		}
		if(it != (--st.end())) {
			auto rb = it; rb++;
			if(*rb - *it > 1) 
				res.insert({*it + 1, *rb - 1});
		}
	}
	return res;
}

template<typename T>
void intersect(set<T> &st, set<T> st1) {
	set<T> st2;
	for(auto x : st1) {
		if(st.count(x)) 
			st2.insert(x);
	}
	st = st2;
}

ll count_rectangles(vector<vector<int>> a) {
	int n = (int)a.size(), m = (int)a[0].size();
	if(n < 3 || m < 3) return 0;
	ll res = 0;
	for(int r1 = 1; r1 < n - 1; r1++) {
		set<pair<int, int>> seg;
		vector<int> mx(m);
		for(int r2 = r1; r2 < n - 1; r2++) {
			
			for(int i = 0; i < m; i++) 
				mx[i] = max(mx[i], a[r2][i]);
			
			vector<int> pre(m);
			for(int i = 0; i < m; i++) {
				pre[i] = (mx[i] < min(a[r1 - 1][i], a[r2 + 1][i]));
				if(i) pre[i] += pre[i - 1];
			}
			if(r1 == r2) seg = get_segments(a[r2]);
			else intersect(seg, get_segments(a[r2]));
			for(auto [l, r] : seg) {
				int x = pre[r] - (l ? pre[l - 1] : 0);
				if(x == r - l + 1) 	
					res++;
			}
		}
	}
	return res;
}

• 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