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Submission #475438

# Submission time Handle Problem Language Result Execution time Memory
475438 2021-09-22T11:55:53 Z MohamedAhmed04 Pipes (CEOI15_pipes) C++14
100 / 100
 1446 ms 10264 KB 
#include <bits/stdc++.h>
 
using namespace std ;
 
const int MAX = 1e5 + 10 ;
 
int P[MAX] , P1[MAX] , sz1[MAX] , P2[MAX] , mark[MAX] , dep[MAX] ;
 
int n , m ;
 
vector< vector<int> >adj(MAX) ;
 
void init()
{
	for(int i = 1 ; i <= n ; ++i)
		P1[i] = i , sz1[i] = 1 ;
}
 
int root(int node)
{
	return P1[node] ;
}
 
int r = -1 ;

void dfs(int node , int par , bool flag)
{
	P1[node] = r ;
	for(auto &child : adj[node])
	{
		if(child == par)
			continue ;
		dep[child] = dep[node] + 1 ;
		if(P[node] == child)
			dfs(child , node , mark[node]) ;
		else
			dfs(child , node , mark[child]) ;
	}
	P[node] = P2[node] = par , mark[node] = flag ;
}
 
void Union(int x , int y)
{
	int a = root(x) ;
	int b = root(y) ;
	if(sz1[a] < sz1[b])
		swap(a , b) , swap(x , y) ;
	adj[x].push_back(y) , adj[y].push_back(x) ;
	dep[y] = dep[x] + 1 , r = a ; 
	dfs(y , x , 0) ;
	sz1[a] += sz1[b] ;
}
 
vector<int>v1 , v2 ;
 
void solve(int x , int y)
{
	while(x != y)
	{
		while(dep[x] >= dep[y] && x != y)
			v1.push_back(x) , mark[x] = 1 , x = P2[x] ;
		while(dep[y] >= dep[x] && x != y)
			v2.push_back(y) , mark[y] = 1 , y = P2[y] ;
	}
	for(auto &node : v1)
		P2[node] = x ;
	for(auto &node : v2)
		P2[node] = y ;
	v1.clear() , v2.clear() ;
}
 
int main()
{
	ios_base::sync_with_stdio(0) ;
	cin.tie(0) ;
	cin>>n>>m ;
	init() ;
	for(int i = 0 ; i < m ; ++i)
	{
		int x , y ;
		cin>>x>>y ;
		if(root(x) != root(y))
			Union(x , y) ;
		else
			solve(x , y) ;
	}
	for(int i = 1 ; i <= n ; ++i)
	{
		if(!mark[i] && P[i])
			cout<<i<<" "<<P[i]<<"\n" ;
	}
	return 0 ;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 2892 KB Output is correct
2 Correct 5 ms 2892 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 129 ms 2892 KB Output is correct
2 Correct 126 ms 2764 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 212 ms 3188 KB Output is correct
2 Correct 253 ms 3148 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 368 ms 3916 KB Output is correct
2 Correct 296 ms 4336 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 497 ms 6536 KB Output is correct
2 Correct 408 ms 6468 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 783 ms 7048 KB Output is correct
2 Correct 702 ms 7096 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 968 ms 8180 KB Output is correct
2 Correct 943 ms 8204 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1171 ms 8228 KB Output is correct
2 Correct 1109 ms 8348 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1446 ms 7852 KB Output is correct
2 Correct 1402 ms 10264 KB Output is correct