Submission #669287

#	Time	Username	Problem	Language	Result	Execution time	Memory
669287		manizare	Pipes (CEOI15_pipes)	C++14	10 / 100	1006 ms	22428 KiB

pipes

#include <bits/stdc++.h>
#define all(a) a.begin(),a.end() 
#define pb push_back
#define int long long 
using namespace std ;
const int maxn = 1e5+10 , maxq =5002 , inf = 2e17 + 100 , mod = 1e9 + 7 ;
vector <int >G[maxn] ;
int par[maxn] , par2[maxn] , p[maxn] , dp[maxn] , mark[maxn] , dis[maxn];
int find(int v){
	if(par[v] == v)return v; 
	return par[v] = find(par[v]);
}
int find2(int v){
	if(par2[v] == v)return v; 
	return par2[v] = find2(par2[v]) ;
}

void dfs(int v){
	mark[v] = 1; 
	for(int i = 0 ; i < G[v].size() ; i++){
		int u = G[v][i] ;
		if(mark[u] == 1){
			if(dis[u] < (dis[v] - 1)) {
				dp[v] ++ ;
				dp[u]--;
			}
			continue ;
		}
		dis[u] = dis[v] + 1; 
		p[u] = v; 
		dfs(u);
		dp[v] += dp[u] ;
	}
}

signed main(){	
	ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
	int n , m ;
	cin >> n >> m ;
	for(int i= 1 ; i <= n ; i++){
		par[i] = i ;
		par2[i] = i ; 
	}
	for(int i =1 ; i <= m ; i++){
		int v  , u ;
		cin >> v >> u ;
		int v1 = find(v) , u1 = find(u);
		if(v1 != u1){
			G[v].pb(u) ;
			G[u].pb(v);
			par[v1] = u1 ;
		}else if(find2(v) != find2(u)){
			par2[find2(v)] = find2(u);
			G[v].pb(u) ;
			G[u].pb(v);
		}
	}
	for(int i = 1; i <= n ; i++){
		if(mark[i] == 0)dfs(i); 
	}
	for(int i = 1; i <= n ; i++){
		if(dp[i] == 0 && p[i] != 0){
			cout << i << " " << p[i] << "\n";
		}
	}
}

Compilation message (stderr)

pipes.cpp: In function 'void dfs(long long int)':
pipes.cpp:20:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |  for(int i = 0 ; i < G[v].size() ; i++){
      |                  ~~^~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 10 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10