Submission #1068242

#	Time	Username	Problem	Language	Result	Execution time	Memory
1068242		pcc	Rectangles (IOI19_rect)	C++17	0 / 100	5037 ms	77048 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
using namespace std;

#pragma GCC target("avx2,popcnt,sse4")
#pragma GCC optimize("O3,unroll-loops")
#define ll long long


vector<vector<int>> pref,arr,row,col;
int N,M;

int sum(int sr,int er,int sc,int ec){
	sr++,er++,sc++,ec++;
	return pref[er][ec]-pref[sr-1][ec]-pref[er][sc-1]+pref[sr-1][sc-1];
}

long long count_rectangles(std::vector<std::vector<int> > a) {
	N = a.size(),M = a[0].size();
	pref = vector<vector<int>>(N+1,vector<int>(M+1,0));
	row = col = pref;
	arr = a;
	for(int i = 0;i<N;i++){
		for(int j = 0;j<M;j++){
			pref[i+1][j+1] = arr[i][j];
		}
	}
	for(int i = 1;i<=N;i++){
		for(int j = 1;j<=M;j++){
			pref[i][j] += pref[i-1][j]+pref[i][j-1]-pref[i-1][j-1];
		}
	}
	ll ans = 0;
	for(int i = 0;i<N;i++){
		for(int j = 0;j<M;j++){
			if(arr[i][j]){
				row[i][j] = col[i][j] = 0;
				continue;
			}
			if(i)col[i][j] = col[i-1][j]+1;
			else col[i][j] = 1;
			if(j)row[i][j] = row[i][j-1]+1;
			else row[i][j] = 1;
		}
	}

	/*
	cerr<<"ROW: "<<endl;
	for(int i = 0;i<N;i++){
		for(int j = 0;j<M;j++)cerr<<row[i][j]<<' ';cerr<<endl;
	}cerr<<endl;

	cerr<<"COL: "<<endl;
	for(int i = 0;i<N;i++){
		for(int j = 0;j<M;j++)cerr<<col[i][j]<<' ';cerr<<endl;
	}cerr<<endl;
	*/

	for(int i = 1;i+1<N;i++){
		for(int j = 1;j+1<M;j++){
			if(!row[i][j])continue;
			int h = col[i][j],w = row[i][j];
			if(i<h||j<w)continue;
			if(sum(i-h+1,i,j-w+1,j) == 0){
				cerr<<"ZERO: "<<i<<' '<<j<<":"<<h<<' '<<w<<endl;
			}
			if(sum(i-h+1,i,j+1,j+1) == sum(i-h+1,i,j-w,j-w) && sum(i-h+1,i,j+1,j+1) == h&&
				sum(i-h,i-h,j-w+1,j) == sum(i+1,i+1,j-w+1,j)&&sum(i-h,i-h,j-w+1,j) == w&&
					sum(i-h+1,i,j-w+1,j) == 0)ans++;
		}
	}
	return ans;
}

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