Submission #1054657

#	Time	Username	Problem	Language	Result	Execution time	Memory
1054657		dozer	Rectangles (IOI19_rect)	C++14	0 / 100	193 ms	590332 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
using namespace std;
#define sp " "
#define endl "\n"
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define LL node * 2
#define RR node * 2 + 1
#define ll long long
#define MAXN 2505
#define LOGN 12
 
vector<pii> rng_h[MAXN], rng_v[MAXN];
vector<int> hor[MAXN][MAXN], ver[MAXN][MAXN];
vector<int> nxt_hor[MAXN][MAXN], nxt_ver[MAXN][MAXN];

void compute(vector<vector<int>> &a){
	int n = a.size(), m = a.front().size();
	for (int i = 1; i < n - 1; i++){
		vector<int> nxt(m), prv(m);
		nxt[m - 1] = m;
		for (int j = m - 2; j >= 0; j--){
			nxt[j] = j + 1;
			while(nxt[j] < m && a[i][nxt[j]] < a[i][j]) nxt[j] = nxt[nxt[j]];
		}
		prv[0] = -1;
		for (int j = 1; j < m; j++){
			prv[j] = j - 1;
			while(prv[j] != -1 && a[i][prv[j]] < a[i][j]) prv[j] = prv[prv[j]];
		}

		for (int j = 1; j < m - 1; j++)
			if (prv[j] != -1 && nxt[j] != m && prv[j] < nxt[j] + 1) rng_h[i].pb({prv[j] + 1, nxt[j] - 1});
		
	}

	swap(n, m);
	for (int i = 1; i < n - 1; i++){
		vector<int> nxt(m), prv(m);
		nxt[m - 1] = m;
		for (int j = m - 2; j >= 0; j--){
			nxt[j] = j + 1;
			while(nxt[j] < m && a[nxt[j]][i] < a[j][i]) nxt[j] = nxt[nxt[j]];
		}
		prv[0] = -1;
		for (int j = 1; j < m; j++){
			prv[j] = j - 1;
			while(prv[j] != -1 && a[prv[j]][i] < a[j][i]) prv[j] = prv[prv[j]];
		}

		for (int j = 1; j < m - 1; j++)
			if (prv[j] != -1 && nxt[j] != m && prv[j] < nxt[j] + 1) rng_v[i].pb({prv[j] + 1, nxt[j] - 1});
	}
}
 
 
int b_search(vector<int> &v, int pos){
	int ans = pos;
	for (int i = LOGN; i >= 0; i--){
		int tmp = ans + (1<<i);
		if (tmp >= v.size()) continue;
		if (v[tmp] - v[pos] == tmp - pos) ans = tmp;
	}
	return ans;
}
 
int tree[MAXN];

void update(int x, int val, int n){
	while(x <= n){
		tree[x] += val;
		x+=x&-x;
	}
}


int query(int x){
	int ans = 0;
	while(x > 0) {
		ans += tree[x];
		x-=x&-x;
	}
	return ans;
}

long long count_rectangles(vector<vector<int>> a){
	compute(a);
	
	int n = a.size(), m = a.front().size();
	for (int i = 1; i < n - 1; i++){
		sort(rng_h[i].begin(), rng_h[i].end());

		for (auto j : rng_h[i]){
			hor[j.st][j.nd].pb(i);
		}
	}
 
	for (int i = 1; i < m - 1; i++){
		sort(rng_v[i].begin(), rng_v[i].end());
		for (auto j : rng_v[i]){
			ver[j.st][j.nd].pb(i);
		}
	}

	long long ans = 0;
	
	for (int i = 1; i < n - 1; i++){
		for (int j = 1; j < m - 1; j++){
			vector<pii> horr, verr;
			int pos = lower_bound(rng_h[i].begin(), rng_h[i].end(), make_pair(j, 0)) - rng_h[i].begin(); 	
			while(pos != rng_h[i].size() && rng_h[i][pos].st == j){
				int l = j, r = rng_h[i][pos].nd;
				pos++;
				int curr = lower_bound(hor[l][r].begin(), hor[l][r].end(), i) - hor[l][r].begin();
				int to = hor[l][r][b_search(hor[l][r], curr)];
				horr.pb({r, to});
			}

			pos = lower_bound(rng_v[j].begin(), rng_v[j].end(), make_pair(i, 0)) - rng_v[j].begin();
			while(pos != rng_v[j].size() && rng_v[j][pos].st == i){
				int l = i, r = rng_v[j][pos].nd;
				pos++;
				int curr = lower_bound(ver[l][r].begin(), ver[l][r].end(), j) - ver[l][r].begin();
				int to = ver[l][r][b_search(ver[l][r], curr)];
				verr.pb({to, r});
			}
			sort(horr.begin(), horr.end());
			sort(verr.begin(), verr.end());

			int it = 0;
			vector<int> del;
			for (auto k : verr){
				
				while(it < horr.size() && horr[it].st <= k.st){
					del.pb(horr[it].nd);
					update(horr[it].nd, 1, n);
					it++;
				}
				ans += query(n) - query(k.nd - 1);
			}

			for (auto i : del){
				update(i, -1, n);
			}
		}
	}
	return ans;
 
	return 0;
}
 
 /*

int main() {
	fileio();
	int n, m;
	cin>>n>>m;
	vector<vector<int>> a(n, vector<int>(m));
	for (int i = 0; i < n; i++)	{
		for (int j = 0; j < m; j++) {
			cin>>a[i][j];
		}
	}
	long long result = count_rectangles(a);
 
	printf("%lld\n", result);
	return 0;
}*/

Compilation message (stderr)

rect.cpp: In function 'int b_search(std::vector<int>&, int)':
rect.cpp:66:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   66 |   if (tmp >= v.size()) continue;
      |       ~~~~^~~~~~~~~~~
rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:116:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  116 |    while(pos != rng_h[i].size() && rng_h[i][pos].st == j){
      |          ~~~~^~~~~~~~~~~~~~~~~~
rect.cpp:125:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |    while(pos != rng_v[j].size() && rng_v[j][pos].st == i){
      |          ~~~~^~~~~~~~~~~~~~~~~~
rect.cpp:139:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  139 |     while(it < horr.size() && horr[it].st <= k.st){
      |           ~~~^~~~~~~~~~~~~

• 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