Submission #297655

#	Time	Username	Problem	Language	Result	Execution time	Memory
297655		shayan_p	Rectangles (IOI19_rect)	C++17	10 / 100	5012 ms	70044 KiB

rect

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

#define F first
#define S second
#define PB push_back
#define sz(s) (int(s.size()))
#define bit(n, k) (((n)>>(k))&1)

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int maxn = 2510;

int aftx[maxn][maxn], befx[maxn][maxn], afty[maxn][maxn], befy[maxn][maxn];

ll count_rectangles(vector< vector<int> > a){
    int n = sz(a);
    int m = sz(a[0]);
    /*
    for(int i = 0; i < n; i++){
	for(int j = 0; j < m; j++){
	    befx[i][j] = j-1;
	    while(befx[i][j] >= 0 && a[i][befx[i][j]] <= a[i][j])
		befx[i][j] = befx[i][ befx[i][j] ];
	}
	for(int j = m-1; j >= 0; j--){
	    aftx[i][j] = j+1;
	    while(aftx[i][j] < m && a[i][aftx[i][j]] <= a[i][j])
		aftx[i][j] = aftx[i][ aftx[i][j] ];
	}
    }
    for(int j = 0; j < m; j++){
	for(int i = 0; i < n; i++){
	    befy[i][j] = i-1;
	    while(befy[i][j] >= 0 && a[befy[i][j]][j] <= a[i][j])
		befy[i][j] = befy[ befy[i][j] ][j];
	}
	for(int i = n-1; i >= 0; i--){
	    afty[i][j] = i+1;
	    while(afty[i][j] < n && a[afty[i][j]][j] <= a[i][j])
		afty[i][j] = afty[ afty[i][j] ][j];
	}	
    }
    */

    for(int i = 0; i < n; i++){
	for(int j = 0; j < m; j++){
	    befx[i][j] = j-1;
	    while(befx[i][j] >= 0 && a[i][befx[i][j]] <= a[i][j])
		befx[i][j]--;
	}
	for(int j = m-1; j >= 0; j--){
	    aftx[i][j] = j+1;
	    while(aftx[i][j] < m && a[i][aftx[i][j]] <= a[i][j])
		aftx[i][j]++;
	}
    }
    for(int j = 0; j < m; j++){
	for(int i = 0; i < n; i++){
	    befy[i][j] = i-1;
	    while(befy[i][j] >= 0 && a[befy[i][j]][j] <= a[i][j])
		befy[i][j]--;
	}
	for(int i = n-1; i >= 0; i--){
	    afty[i][j] = i+1;
	    while(afty[i][j] < n && a[afty[i][j]][j] <= a[i][j])
		afty[i][j]++;
	}	
    }

    
    ll ans = 0;
    for(int i = 0; i < n; i++){
	for(int j = 0; j < m; j++){
	    if(befx[i][j] == -1 || befy[i][j] == -1 || aftx[i][j] == m || afty[i][j] == n)
		continue;
	    bool ok = 1;
	    for(int x = befy[i][j] + 1; x < afty[i][j]; x++){
		for(int y = befx[i][j] + 1; y < aftx[i][j]; y++){
		    if((pii){x, y} < (pii){i, j})
			ok&= a[x][y] < a[i][j];
		    ok&= befx[x][y] >= befx[i][j];
		    ok&= befy[x][y] >= befy[i][j];
		    ok&= aftx[x][y] <= aftx[i][j];
		    ok&= afty[x][y] <= afty[i][j];
		}
	    }
	    ans+= ok;
	}
    }
    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