Submission #986582

#	Time	Username	Problem	Language	Result	Execution time	Memory
986582		mariaclara	Rectangles (IOI19_rect)	C++17	13 / 100	698 ms	284500 KiB

rect

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

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
const int MAXVAL = 2;
#define all(x) x.begin(), x.end()
#define SZ(x) x.size()
#define mk make_pair
#define pb push_back
#define fr first
#define sc second

pii pai[2505][2505];
int sz[2505][2505], r1[2505][2505], r2[2505][2505], c1[2505][2505], c2[2505][2505];
int op[4] = {0,0,1,-1};

pii find(pii x) {
	if(pai[x.fr][x.sc] == x) return x;
	return pai[x.fr][x.sc] = find(pai[x.fr][x.sc]);
}

void join(pii x, pii y) {
	x = find(x);
	y = find(y);

	if(x == y) return;
	r1[y.fr][y.sc] = r1[x.fr][x.sc] = min(r1[y.fr][y.sc], r1[x.fr][x.sc]);
	c1[y.fr][y.sc] = c1[x.fr][x.sc] = min(c1[y.fr][y.sc], c1[x.fr][x.sc]);
	r2[y.fr][y.sc] = r2[x.fr][x.sc] = max(r2[y.fr][y.sc], r2[x.fr][x.sc]);
	c2[y.fr][y.sc] = c2[x.fr][x.sc] = max(c2[y.fr][y.sc], c2[x.fr][x.sc]);
	if(sz[x.fr][x.sc] < sz[y.fr][y.sc]) {
		pai[x.fr][x.sc] = y;
		sz[y.fr][y.sc] += sz[x.fr][x.sc];
	}
	else {
		pai[y.fr][y.sc] = x;
		sz[x.fr][x.sc] += sz[y.fr][y.sc];
	}
}
ll count_rectangles(vector<vector<int>> a) {
	int n = SZ(a), m = SZ(a[0]);
	vector<vector<pii>> val(MAXVAL);
	vector<vector<bool>> in_set(n), aux(n);

	for(int i = 0; i < n; i++){
		in_set[i].resize(m);
		aux[i].resize(m);
		for(int j = 0; j < m; j++){
			val[a[i][j]].pb({i,j});
			pai[i][j] = mk(i,j);
			sz[i][j] = 1;
			r1[i][j] = r2[i][j] = i;
			c1[i][j] = c2[i][j] = j;
		}
	}

	int ans = 0;
	for(int num = 0; num < MAXVAL; num++) {
		for(auto [x,y] : val[num]) {
			in_set[x][y] = 1;
			for(int i = 0; i < 4; i++) {
				int a = x+op[i], b = y+op[3-i];
				if(a >= 0 and b >= 0 and a < n and b < m and in_set[a][b]) 
					join(mk(x,y),mk(a,b));
			}
		}

		for(auto it : val[num]) {
			auto [x,y] = find(it);
			if(aux[x][y]) continue;
			if(r1[x][y] == 0 or c1[x][y] == 0 or r2[x][y] == n-1 or c2[x][y] == m-1) continue;
			if( (r2[x][y] - r1[x][y] + 1) * (c2[x][y] - c1[x][y] + 1) == sz[x][y] ) aux[x][y] = 1, ans++;
		}

		for(auto it : val[num]) {
			auto [x,y] = find(it);
			aux[x][y] = 0;
		}

	}

	return ans;
}

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