Submission #836440

#	Time	Username	Problem	Language	Result	Execution time	Memory
836440		Antekb	Rectangles (IOI19_rect)	C++17	100 / 100	1848 ms	89168 KiB

rect

#include<bits/stdc++.h>
#include "rect.h"
#define st first
#define nd second
#define pb push_back
#define eb emplace_back
#define pp pop_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
using namespace std;
using pii = pair<int, int>;
using vi = vector<int>;
using vii = vector<pii>;
using ll = long long;

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

void debug(){cerr<<"\n";}
template<typename H, typename... T>
void debug(H h, T... t){
	cerr<<h;
	if(sizeof...(t))cerr<<", ";
	debug(t...);
}
#define deb(x...) cerr<<#x<<" = ";debug(x);

const int N=2505;

ll count_rectangles(std::vector<std::vector<int> > tab) {
	int n=tab.size(), m=tab[0].size();
	if(m<=2 || n<=2)return 0;
	vector<vi> V2(m, {0});
	for(int i=0; i<m; i++){
		if(tab[1][i]>=tab[0][i]){
			V2[i]={1};
		}
		else V2[i]={0, 1};
	}
	/*for(int i=0; i<n; i++){
		for(int j=0; j<m; j++){
			//deb(i, j);
			for(int k:par[i][j]){
				//deb(k);
			}
		}
	}*/
	vector<pii> prv;
	vi dp2;
	ll ans=0;
	vector<bitset<N> > suf(n);
	for(int i=0; i<n; i++){
		for(int j=i; j<n; j++)suf[i][j]=1;
	}
	for(int r=1; r<n-1; r++){
		vector<bitset<N>> par(m);
		for(int i=1; i<m-1; i++){
			while(V2[i].size() && tab[r+1][i]>tab[V2[i].back()][i]){
				if(V2[i].back()!=r)par[i][V2[i].back()]=1;
				V2[i].pp();
			}
			if(V2[i].size() && V2[i].back()!=r)par[i][V2[i].back()]=1;
			if(V2[i].size() && tab[V2[i].back()][i]==tab[r+1][i])V2[i].pp();
			V2[i].pb(r+1);
		}
	vector<pii> akt;
		vi dp;
		vi V={m-1};
		for(int j=m-2; j>=0; j--){
			while(V.size() && tab[r][j]>tab[r][V.back()]){
				if(V.back()!=j+1){
					akt.eb(j, V.back());
				}
				V.pp();
			}
			if(V.size() && V.back()!=j+1){
				akt.eb(j, V.back());
			}
			if(V.size() && tab[r][V.back()]==tab[r][j])V.pp();
			V.pb(j);
		}
		dp.resize(akt.size(), 1);
		int wsk=0;
		for(int i=0; i<akt.size(); i++){
			while(wsk<prv.size() && (akt[i].st<prv[wsk].st 
				|| (akt[i].st==prv[wsk].st && akt[i].nd>prv[wsk].nd)))wsk++;
			if(wsk<prv.size() && akt[i]==prv[wsk])dp[i]+=dp2[wsk];
		}
		vi wsk2(m);
		vector<int> S;
		vector<bitset<N> > b(akt.size());
		for(int i=0; i<akt.size(); i++){
			//deb(r, i, akt[i].st, akt[i].nd, dp[i]);
			b[i]=suf[0];
			//for(int k=r-1; k>=r-dp[i]; k--)b[i][k]=1;
			int pocz=akt[i].st+1;
			while(S.size()){
				int a=S.back();
				if(akt[a].st>=akt[i].nd)break;
				S.pp();
				for(;pocz<=akt[a].st;pocz++){
					b[i]&=par[pocz];
				}
				b[i]&=b[a];
				pocz=akt[a].nd;
			}
			S.pb(i);
			/*for(int j=0; j<i; j++){
				if(akt[i].nd>=akt[j].nd){
					assert(dp[i]<=dp[j]);
					b[i]&=b[j];
				}
			}*/
			for(;pocz<akt[i].nd;pocz++){
				b[i]&=par[pocz];
			}
			ans+=(b[i]&suf[r-dp[i]]).count();
			/*for(int k=r-1; k>=r-dp[i]; k--){
				if(b[i][k]){
					//deb(r, akt[i].st, akt[i].nd, k);
					ans++;
				}
			}*/
		}
		prv=akt;
		dp2=dp;
	}
	return ans;
}

Compilation message (stderr)

rect.cpp: In function 'll count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:83:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |   for(int i=0; i<akt.size(); i++){
      |                ~^~~~~~~~~~~
rect.cpp:84:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |    while(wsk<prv.size() && (akt[i].st<prv[wsk].st
      |          ~~~^~~~~~~~~~~
rect.cpp:86:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |    if(wsk<prv.size() && akt[i]==prv[wsk])dp[i]+=dp2[wsk];
      |       ~~~^~~~~~~~~~~
rect.cpp:91:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |   for(int i=0; i<akt.size(); i++){
      |                ~^~~~~~~~~~~

• 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: 28 / 28