Submission #583622

#	Time	Username	Problem	Language	Result	Execution time	Memory
583622		Lucpp	Rectangles (IOI19_rect)	C++17	10 / 100	365 ms	440968 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
using namespace std;
#define sz(x) ((int)(x).size())
typedef long long ll;
 
vector<int> fen;
void add(int i, int x){
	for(i++; i < sz(fen); i+=i&-i) fen[i] += x;
}
int qry(int i){
	int ans = 0;
	for(i++; i > 0; i-=i&-i) ans += fen[i];
	return ans;
}
int qry(int i, int j){
	if(i > 0) return qry(j)-qry(i-1);
	else return qry(j);
}

long long count_rectangles(vector<vector<int>> a) {
	int n = sz(a), m = sz(a[0]);
	vector<vector<short>> r1(n, vector<short>(m, -1)), r2(n, vector<short>(m, -1));
	for(int i = 1; i < n-1; i++){
		stack<pair<int, int>> st({{a[i][0], 0}});
		for(int j = 1; j < m; j++){
			while(!st.empty() && a[i][j] > st.top().first){
				auto [h, k] = st.top();
				st.pop();
				r2[i][k] = j-1;
			}
			if(!st.empty()) {
				if(st.top().first > a[i][j]) r1[i][j] = st.top().second+1;
				else r1[i][j] = r1[i][st.top().second];
			}
			st.emplace(a[i][j], j);
		}
	}
	vector<vector<short>> c1(n, vector<short>(m, -1)), c2(n, vector<short>(m, -1));
	for(int j = 1; j < m-1; j++){
		stack<pair<int, int>> st({{a[0][j], 0}});
		for(int i = 1; i < n; i++){
			while(!st.empty() && a[i][j] > st.top().first){
				auto [h, k] = st.top(); st.pop();
				c2[k][j] = i-1;
			}
			if(!st.empty()){
				if(st.top().first > a[i][j]) c1[i][j] = st.top().second+1;
				else c1[i][j] = c1[st.top().second][j];
			}
			st.emplace(a[i][j], i);
		}
	}
	a.clear();
	a.shrink_to_fit();
	int mx = max(n, m);
	fen.resize(mx+1);
	vector<bool> valid;
	vector<vector<pair<int, int>>> byI(mx*mx);
	unordered_set<ll> noDupl;
	vector<vector<int>> goodI(mx*mx), goodJ(mx*mx);
	int q = 0;
	int ans = 0;
	for(int i = 1; i < n-1; i++){
		for(int j = 1; j < m-1; j++){
			// cerr << "\n" << i << " " << j << " " << r1[i][j] << " " << r2[i][j] << " " << c1[i][j] << " " << c2[i][j] << "\n";
			if(r1[i][j] != -1 && r2[i][j] != -1 && c1[i][j] != -1 && c2[i][j] != -1){
				int x = c1[i][j]*mx + c2[i][j], y = r1[i][j]*mx + r2[i][j];
				goodJ[x].push_back(j);
				goodI[y].push_back(i);
				if(r1[i][j] == r2[i][j] && c1[i][j] == c2[i][j]){
					ans++;
					continue;
				}
				ll t = (ll)x*mx*mx+y;
				if(noDupl.count(t)) continue;
				noDupl.insert(t);
				valid.push_back(true);
				byI[x].emplace_back(y, q);
				q++;
			}
		}
	}
	vector<bool> used(mx);
	for(int id = 1; id < mx*mx; id++){
		int added = 0;
		for(int j : goodJ[id]){
			if(!used[j]) add(j, 1), added++;
			used[j] = true;
		}
		for(auto [id2, ind] : byI[id]){
			int L = id2/mx, R = id2%mx;
			if(added >= R-L+1 && qry(L, R) != R-L+1) valid[ind] = false;
		}
		for(int j : goodJ[id]){
			if(used[j]) add(j, -1);
			used[j] = false;
		}
	}
	noDupl = unordered_set<ll>();
	goodJ = vector<vector<int>>();

	vector<vector<pair<int, int>>> byJ(mx*mx);
	for(int id = 1; id < mx*mx; id++){
		for(auto [id2, ind] : byI[id]){
			byJ[id2].emplace_back(id, ind);
		}
	}
	for(int id = 1; id < mx*mx; id++){
		int last = -1, added = 0;
		for(int i : goodI[id]){
			if(i != last) add(i, 1), added++;
			last = i;
		}
		for(auto [id2, ind] : byJ[id]){
			int L = id2/mx, R = id2%mx;
			if(added >= R-L+1 && qry(L, R) != R-L+1) valid[ind] = false;
		}
		last = -1;
		for(int i : goodI[id]){
			if(i != last) add(i, -1);
			last = i;
		}
	}
	for(bool b : valid) ans += b;
	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