# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
857871 | UmairAhmadMirza | Pipes (CEOI15_pipes) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
//In the name of Allah the most beneficent, the most merciful.
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,avx512,fma")
const int N = 5005;
// -------------------------<RNG>-------------------------
//--------------------------------------------------------
vector<int> adj[N];
int e1,e2;
bool vis[N];
int n,m;
void dfs(int node){
vis[node]=1;
bool b=0;
for(auto i:adj[node]){
if((b==0) && (((node==e1)&&(i==e2)) || ((node==e2)&&(i==e1)))){
b=1;
continue;
}
if(vis[i]==0)
dfs(i);
}
}
bool check(pair<int,int> e){
e1=e.first;
e2=e.second;
for(int i=0;i<=n;i++)
vis[i]=0;
dfs(e1);
return !(vis[e2]);
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin>>n>>m;
vector<pair<int,int>> ed;
for(int i=0;i<m;i++){
int a,b;
cin>>a>>b;
adj[a].push_back(b);
adj[b].push_back(a);
ed.push_back({a,b});
}
for(auto e:ed)
if(check(e))
cout<<e.first<<' '<<e.second<<endl;
}