Submission #291797

#	Time	Username	Problem	Language	Result	Execution time	Memory
291797		pit4h	Rectangles (IOI19_rect)	C++14	100 / 100	3685 ms	833200 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
#define ll long long
#define st first
#define nd second
#define mp make_pair
using namespace std;
using vec2d = vector<vector<pair<int, int>>>;
int n, m;
struct Segment {
	int l, r, h;
};
ll solve(vector<Segment> a, vector<Segment> b) {
	ll res = 0;
	int nrA = 0, nrB = 0;
	vector<vector<int>> A(m+1), B(m+1);
	for(auto i: a) {
		A[i.h].push_back(nrA);
		nrA++;
	}
	for(auto i: b) {
		B[i.h].push_back(nrB);
		nrB++;
	}
	vector<vector<int>> cnt(n);
	vector<bool> occured(nrA);
	for(int h=m; h>=1; --h) {
		for(int i: A[h]) {
			cnt[a[i].l].push_back(i);
			cnt[a[i].r].push_back(i);
		}
		for(int i: B[h]) {
			for(int j=b[i].l; j<=b[i].r; ++j) {
				for(int k: cnt[j]) {
					if(occured[k]) res++;
					occured[k] = occured[k] ^ 1;
				}
			}
			for(int j=b[i].l; j<=b[i].r; ++j) {
				for(int k: cnt[j]) {
					occured[k] = occured[k] ^ 1;
				}
			}
		}
	}
	return res;
}
ll count_rectangles(vector<vector<int>> a) {
	n = a.size();
	m = a[0].size();
	vector<vec2d> horiz(n, vec2d(m));
	for(int i=0; i<n; ++i) {
		vector<int> mono;
		for(int j=0; j<m; ++j) {
			while(mono.size() && a[i][mono.back()] < a[i][j]) {
				if(mono.back()+1 <= j-1) {
					horiz[i][mono.back()+1].push_back(mp(j-1, 1));
				}
				mono.pop_back();
			}
			if(mono.size() && mono.back()+1 <= j-1) {
				horiz[i][mono.back()+1].push_back(mp(j-1, 1));	
			}
			if(mono.size() && a[i][mono.back()] == a[i][j]) {
				mono.pop_back();
			}
			mono.push_back(j);
		}
		if(i!=0) {
			for(int j=0; j<m; ++j) {
				int k = 0;
				for(auto &it: horiz[i][j]) {
					while(k<(int)horiz[i-1][j].size() && horiz[i-1][j][k].st < it.st) {
						k++;
					}
					if(k<(int)horiz[i-1][j].size() && horiz[i-1][j][k].st == it.st) {
						it.nd = horiz[i-1][j][k].nd + 1;
					}
				}
			}
		}
	}
	vector<vector<Segment>> segh(m);
	for(int i=0; i<n; ++i) {
		if(i < n-1) {
			for(int j=0; j<m; ++j) {
				int k = 0;
				for(auto it: horiz[i][j]) {
					while(k<(int)horiz[i+1][j].size() && horiz[i+1][j][k].st < it.st) {
						k++;
					}
					if(k==(int)horiz[i+1][j].size() || horiz[i+1][j][k].st != it.st) {
						segh[j].push_back({i-it.nd+1, i, it.st-j+1});
					}
				}
			}
		}
		else {
			for(int j=0; j<m; ++j) {
				for(auto it: horiz[i][j]) {
					segh[j].push_back({i-it.nd+1, i, it.st-j+1});
				}
			}
		}
	}
	/// **************************************
	/// *** horizontal segments calculated ***
	/// **************************************
	vector<vec2d> vert(m, vec2d(n));
	for(int j=m-1; j>=0; --j) {
		vector<int> mono;
		for(int i=0; i<n; ++i) {
			while(mono.size() && a[mono.back()][j] < a[i][j]) {
				if(mono.back()+1 <= i-1) {
					vert[j][mono.back()+1].push_back(mp(i-1, 1));
				}
				mono.pop_back();
			}
			if(mono.size() && mono.back()+1 <= i-1) {
				vert[j][mono.back()+1].push_back(mp(i-1, 1));
			}
			if(mono.size() && a[mono.back()][j] == a[i][j]) {
				mono.pop_back();
			}
			mono.push_back(i);
		}
		if(j < m-1) {
			for(int i=0; i<n; ++i) {
				int k = 0;
				for(auto &it: vert[j][i]) {
					while(k<(int)vert[j+1][i].size() && vert[j+1][i][k].st < it.st) {
						k++;
					}
					if(k<(int)vert[j+1][i].size() && vert[j+1][i][k].st == it.st) {
						it.nd = vert[j+1][i][k].nd + 1;
					}
				}
			}
		}
	}

	vector<vector<Segment>> segv(m);
	for(int j=m-1; j>=0; --j) {
		for(int i=0; i<n; ++i) {
			for(auto it: vert[j][i]) {
				segv[j].push_back({i, it.st, it.nd});
			}
		}
	}
	ll ans = 0;
	for(int col=0; col<m; ++col) {
		ans += solve(segv[col], segh[col]);
	}
	return ans;
}

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