Submission #516266

#	Time	Username	Problem	Language	Result	Execution time	Memory
516266		MohamedAhmed04	Long Mansion (JOI17_long_mansion)	C++14	0 / 100	176 ms	26036 KiB

long_mansion

#include <bits/stdc++.h>

using namespace std ;

const int MAX = 5e5 + 10 ;

int arr[MAX] ;
int n ;

vector<int>v[MAX] ;

int par[MAX] , sz[MAX] ;
int L[MAX] , R[MAX] ;

int mark[MAX] ;

void init()
{
	for(int i = 1 ; i <= n ; ++i)
	{
		par[i] = i , sz[i] = 1 ;
		L[i] = R[i] = i ;
	}
}

int root(int node)
{
	if(par[node] == node)
		return node ;
	return (par[node] = root(par[node])) ;
}

void Union(int x , int y)
{
	int a = root(x) ;
	int b = root(y) ;
	if(a == b)
		return ;
	par[b] = a ;
	sz[a] += sz[b] ;
	L[a] = min(L[a] , L[b]) , R[a] = max(R[a] , R[b]) ;
}

bool HaveKey(int x , int y)
{
	x = root(x) ;
	int idx = lower_bound(v[y].begin() , v[y].end() , L[x]) - v[y].begin() ;
	if(idx == v[y].size())
		return false ;
	else
		return (v[y][idx] <= R[x]) ;
}

int main()
{
	ios_base::sync_with_stdio(0) ;
	cin.tie(0) ;
	cin>>n ;
	for(int i = 1 ; i <= n-1 ; ++i)
		cin>>arr[i] ;
	for(int i = 1 ; i <= n ; ++i)
	{
		int sz ;
		cin>>sz ;
		v[i].resize(sz) ;
		for(auto &j : v[i])
		{
			cin>>j ;
			v[j].push_back(i) ;
		}
	}
	init() ;
	stack<int>sr , sl ;
	sr.push(n) , sl.push(n) ;
	for(int i = n-1 ; i >= 1 ; --i)
	{
		while(sr.size())
		{
			int idx = sr.top() ;
			int x = root(i) ;
			if(HaveKey(x , arr[idx-1]))
				R[x] = max(R[x] , R[root(idx)]) , sr.pop() ;
			else
				break ;
		}
		while(sl.size())
		{
			int idx = sl.top() ;
			int y = root(idx) ;
			if(HaveKey(y , arr[i]))
				break ;
			else
				L[y] = i+1 , sl.pop() ;
		}
		while(sl.size())
		{
			int idx = sl.top() ;
			int x = root(i) , y = root(idx) ;
			if(R[x] == R[y]) // same component
				Union(i , idx) , sl.pop() ;
			else
				break ;
		}
		sr.push(i) , sl.push(i) ;
	}
	deque<int>d ;
	while(sl.size())
	{
		int idx = sl.top() ;
		int y = root(idx) ;
		L[y] = 1 ;
		d.push_back(y) ;
		sl.pop() ;
	}
	for(int i = 1 ; i <= n ; ++i)
	{
		while(d.size())
		{
			int idx = d.front() ;
			int x = root(idx) ;
			if(R[x] < i && !mark[arr[i-1]])
				d.pop_front() ;
			else
				break ;
		}
		if(!d.size())
			break ;
		int x = root(d.front()) ;
		R[x] = max(R[x] , i) ;
		int y = root(i) ;
		if(L[y] == 1) // was in sl
			Union(x , y) ;
		for(auto &j : v[i])
			mark[j] = 1 ;
	}
	while(d.size())
	{
		int idx = d.front() ;
		d.pop_front() ;
		int y = root(idx) ;
		R[y] = n ;
	}
	int q ;
	cin>>q ;
	while(q--)
	{
		int x , y ;
		cin>>x>>y ;
		x = root(x) ;
		if(L[x] <= y && R[x] >= y)
			cout<<"YES\n" ;
		else
			cout<<"NO\n" ;
	}
	return 0 ;
}		

Compilation message (stderr)

long_mansion.cpp: In function 'bool HaveKey(int, int)':
long_mansion.cpp:48:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |  if(idx == v[y].size())
      |     ~~~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 15
• Subtask 4: 0 / 75