Submission #767788

#	Time	Username	Problem	Language	Result	Execution time	Memory
767788		ono_de206	Rectangles (IOI19_rect)	C++14	72 / 100	5107 ms	267220 KiB

rect

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

#define in insert
#define all(x) x.begin(),x.end()
#define pb push_back
#define eb emplace_back
#define ff first
#define ss second

// #define int long long
 
typedef long long ll;
typedef vector<int> vi;
typedef set<int> si;
typedef multiset<int> msi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;

void mnn(int &a, int b) {
	if(a > b) a = b;
}

void mxx(int &a, int b) {
	if(a < b) a = b;
}

const int mxn = 2510;

namespace sub6 {
	const int dx[] = {1, -1, 0, 0};
	const int dy[] = {0, 0, 1, -1};
	int par[mxn * mxn], cnt[mxn * mxn], n, m;
	pair<pair<int, int>, pair<int, int>> dp[mxn * mxn];
	bool is[mxn][mxn];
	 
	int toInt(pair<int, int> a) {
		return (a.ff - 1) * n + a.ss;
	}
	 
	int get(int x) {
		if(par[x] == x) return x;
		return par[x] = get(par[x]);
	}
	 
	void unite(int x, int y) {
		x = get(x), y = get(y);
		if(x == y) return;
		if(cnt[x] < cnt[y]) swap(x, y);
		par[y] = x;
		cnt[x] += cnt[y];
		mxx(dp[x].ss.ff, dp[y].ss.ff);
		mxx(dp[x].ss.ss, dp[y].ss.ss);
		mnn(dp[x].ff.ff, dp[y].ff.ff);
		mnn(dp[x].ff.ss, dp[y].ff.ss);
	}
	 
	long long count_rectangles(vector<vector<int>> A) {
		n = A.size(), m = A[0].size();
		for(int i = 0; i < n; i++) {
			for(int j = 0; j < m; j++) {
				if(A[i][j] == 0) {
					dp[i * m + j] = {{i, j}, {i, j}};
					par[i * m + j] = i * m + j;
					cnt[i * m + j] = 1; 
				}
			}
		}
		for(int i = 0; i < n; i++) {
			for(int j = 0; j < m; j++) {
				if(A[i][j]) continue;
				for(int k = 0; k < 4; k++) {
					int ii = i + dx[k], jj = j + dy[k];
					if(ii >= 0 && ii < n && jj >= 0 && jj < m && A[ii][jj] == 0) {
						unite(i * m + j, ii * m + jj);
					}
				}
			}
		}
		long long ret = 0;
		set<int> s;
		for(int i = 0; i < n; i++) {
			for(int j = 0; j < m; j++) {
				if(A[i][j] == 1) continue;
				int id = get(i * m + j);
				if(s.find(id) != s.end()) continue;
				s.in(id);
				if((dp[id].ss.ff - dp[id].ff.ff + 1) * (dp[id].ss.ss - dp[id].ff.ss + 1) == cnt[id] && 
					dp[id].ff.ff > 0 && dp[id].ff.ss > 0 && dp[id].ss.ff < n - 1 && dp[id].ss.ss < m - 1) ret++;
			}
		}
		return ret;
	}
}

int n, m, a[mxn][mxn], mx[mxn], fn[mxn];
vector<pair<int, int>> g[mxn];

int get(int i) {
	int ret = 0;
	for(; i > 0; i -= (i & -i)) {
		ret += fn[i];
	}
	return ret;
}

void add(int i, int x) {
	for(; i <= m; i += (i & -i)) {
		fn[i] += x;
	}
} 

long long count_rectangles(vector<vector<int>> A) {
	n = A.size(), m = A[0].size();
	int MX = 0;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= m; j++) {
			a[i][j] = A[i - 1][j - 1];
			if(MX < a[i][j]) MX = a[i][j];
		}
	}
	if(MX <= 1) return sub6::count_rectangles(A); 
	for(int i = 1; i <= n; i++) {
		stack<pair<int, int>> s;
		for(int j = 1; j <= m; j++) {
			while(s.size() && s.top().ff < a[i][j]) {
				if(s.top().ss + 1 < j) g[i].eb(s.top().ss, j);
				s.pop();
			}
			if(s.size()) {
				if(s.top().ss + 1 < j) g[i].eb(s.top().ss, j);
				if(s.top().ff == a[i][j]) {
					s.pop();
				}
			}
			s.push({a[i][j], j});
		}
		sort(all(g[i]));
	}
	long long ans = 0;
	for(int l = 2; l < n; l++) {
		for(int j = 1; j <= m; j++) {
			mx[j] = 0;
			fn[j] = 0;
		}
		vector<pair<int, int>> v;
		for(int r = l; r <= n; r++) {
			for(int j = 1; j <= m; j++) {
				if(mx[j] >= a[r][j]) add(j, 1);
			}
			if(r == l) {
				v = g[r];
			} else {
				for(auto it : v) {
					ans += (get(it.ss - 1) - get(it.ff) == 0);
				}
				vector<pair<int, int>> tmp;
				int id1 = 0, id2 = 0;
				while(id1 < v.size() && id2 < g[r].size()) {
					if(v[id1] == g[r][id2]) {
						tmp.pb(v[id1]);
						id1++;
						id2++;
					} else if(v[id1] < g[r][id2]) {
						id1++;
					} else {
						id2++;
					}
				}
				swap(tmp, v);
			}
			for(int j = 1; j <= m; j++) {
				if(a[r][j] >= a[l - 1][j]) add(j, 1);
				if(mx[j] >= a[r][j]) add(j, -1);
				else {
					mx[j] = a[r][j];
				}
			}
		}
	}
	return ans;
}

Compilation message (stderr)

rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:160:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  160 |     while(id1 < v.size() && id2 < g[r].size()) {
      |           ~~~~^~~~~~~~~~
rect.cpp:160:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  160 |     while(id1 < v.size() && id2 < g[r].size()) {
      |                             ~~~~^~~~~~~~~~~~~

• 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