Submission #597693

#	Time	Username	Problem	Language	Result	Execution time	Memory
597693		FatihSolak	Rectangles (IOI19_rect)	C++17	72 / 100	5092 ms	614984 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
#define N 2505
using namespace std;
struct BIT{
	vector<int> bit;
	int n;
	int tot = 0;
	BIT(int size){
		n = size + 5;
		bit.assign(n+5,0);
	}
	void upd(int pos,int val){
		tot += val;
		for(++pos;pos<n;pos += pos & -pos){
			bit[pos] += val;
		}
	}
	int get(int pos){
		int ret = 0;
		for(++pos;pos > 0;pos -= pos & -pos){
			ret += bit[pos];
		}
		return ret;
	}
	int get(int l,int r){
		return tot - get(l-1);
	}
};
struct SegTree{
	vector<BIT> t;
	int n;
	SegTree(int size){
		n = size + 5;
		t.assign(4*n,BIT(n));
	}
	void upd(int v,int tl,int tr,int l,int r,int val){
		//cout << val << endl;
		t[v].upd(r,val);
		if(tl == tr)return;
		int tm = (tl + tr)/2;
		if(l <= tm){
			upd(v*2,tl,tm,l,r,val);
		}
		else upd(v*2+1,tm+1,tr,l,r,val);
	}
	int get(int v,int tl,int tr,int l,int r){
		if(tr <= l){
			return t[v].get(r,n-1);
		}
		if(tl > l){
			return 0;
		}
		int tm = (tl + tr)/2;
		return get(v*2,tl,tm,l,r) + get(v*2+1,tm+1,tr,l,r);
	}
	void upd(int l,int r,int val){
		upd(1,0,n-1,l,r,val);
	}
	int get(int l,int r){
		return get(1,0,n-1,l,r);
	}
};
int mp[N][N];
int st[N];
vector<int> pos[N];
vector<int> prepos[N];
vector<pair<int,int>> ranges[N][N];
vector<pair<int,int>> queries[N][N];
long long count_rectangles(vector<vector<int>> a){
	auto beg = clock();
	int n = a.size();
	int m = a[0].size();
	//cout << n << " " << m << endl;
	if(n < 3 || m < 3){
		return 0;
	}
	int stsz = 0;
	for(int i = m-1;i>=0;i--){
		stsz = 0;
		for(int j = 0;j<n;j++){
			while(stsz && a[j][i] > a[st[stsz-1]][i])
				stsz--;
			if(stsz && st[stsz-1] != j-1 && a[st[stsz-1]][i] != a[j][i]){
				pos[st[stsz-1]].push_back(j);
			}
			st[stsz++] = j;
		}
		stsz = 0;
		for(int j = n-1;j>=0;j--){
			while(stsz && a[j][i] > a[st[stsz-1]][i])
				stsz--;
			if(stsz && st[stsz-1] != j+1){
				pos[j].push_back(st[stsz-1]);
			}
			st[stsz++] = j;
		}
		for(int j = 0;j<n;j++){
			for(auto u:prepos[j]){
				mp[j][u] = -mp[j][u];
			}
		}
		for(int j = 0;j<n;j++){
			for(auto u:pos[j]){
				mp[j][u] = 1 - mp[j][u];
				if(i)
					queries[i-1][mp[j][u]+1].push_back({j+1,u-1});
				//cout << i << " " << mp[j][u] << " " << j << " " << u << endl;
			}
		}
		for(int j = 0;j<n;j++){
			for(auto u:prepos[j]){
				if(mp[j][u] < 0)
					mp[j][u] = 0;
			}
			swap(prepos[j],pos[j]);
			pos[j].clear();
		}
	}
	for(int i = 0;i<N;i++){
		pos[i].clear();
		prepos[i].clear();
		for(int j = 0;j<N;j++){
			mp[i][j] = 0;
		}
	}
	for(int i = n-1;i>=0;i--){
		stsz = 0;
		for(int j = 0;j<m;j++){
			while(stsz && a[i][j] > a[i][st[stsz-1]])
				stsz--;
			if(stsz && st[stsz-1] != j-1 && a[i][j] != a[i][st[stsz-1]]){
				pos[st[stsz-1]].push_back(j);
			}
			st[stsz++] = j;
		}
		stsz = 0;
		for(int j = m-1;j>=0;j--){
			while(stsz && a[i][j] > a[i][st[stsz-1]])
				stsz--;
			if(stsz && st[stsz-1] != j+1){
				pos[j].push_back(st[stsz-1]);
			}
			st[stsz++] = j;
		}
		for(int j = 0;j<m;j++){
			for(auto u:prepos[j]){
				mp[j][u] = -mp[j][u];
			}
		}
		for(int j = 0;j<m;j++){
			for(auto u:pos[j]){
				mp[j][u] = 1 - mp[j][u];
			}
		}
		for(int j = 0;j<m;j++){
			for(auto u:prepos[j]){
				if(mp[j][u] < 0){
					//cout << j << " " << u << " " << i + 1 << " " << i - mp[j][u] << endl;
					ranges[j][u-j].push_back({i+1,i - mp[j][u]});
					mp[j][u] = 0;
				}
			}
			swap(prepos[j],pos[j]);
			pos[j].clear();
		}
	}
	for(int j = 0;j<m;j++){
		for(auto u:prepos[j]){
			if(mp[j][u] > 0){
				//cout << j << " " << u << " " << -1 + 1 << " " << -1 + mp[j][u] << endl;
				ranges[j][u-j].push_back({-1+1,-1 + mp[j][u]});
				mp[j][u] = 0;
			}
		}
	}
	SegTree tree(n);
	long long ans = 0;
	for(int i = 0;i<m;i++){
		for(int j = 0;j<=m+1;j++){
			for(auto u:ranges[i][j])
				tree.upd(u.first,u.second,1);
			
			for(auto u:queries[i][j])
				ans += tree.get(u.first,u.second);
			
		}
		for(int j = 0;j<=m+1;j++)
			for(auto u:ranges[i][j])
				tree.upd(u.first,u.second,-1);
	}
	return ans;
}

Compilation message (stderr)

rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:71:7: warning: unused variable 'beg' [-Wunused-variable]
   71 |  auto beg = clock();
      |       ^~~

• 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: 0 / 28