Submission #767771

#	Time	Username	Problem	Language	Result	Execution time	Memory
767771		ono_de206	Rectangles (IOI19_rect)	C++14	10 / 100	2 ms	636 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;

const int mxn = 2510;
int n, m, a[mxn][mxn], mx[mxn], fn[mxn];
vector<pair<int, int>> g[mxn];

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

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

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();
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= m; j++) {
			a[i][j] = A[i - 1][j - 1];
		}
	}
	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(mx[j] >= a[r][j]) add(j, -1);
				else {
					if(a[r][j] >= a[l - 1][j]) add(j, 1);
					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:90:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |     while(id1 < v.size() && id2 < g[r].size()) {
      |           ~~~~^~~~~~~~~~
rect.cpp:90:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |     while(id1 < v.size() && id2 < g[r].size()) {
      |                             ~~~~^~~~~~~~~~~~~

• 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