#include <bits/stdc++.h>
#define int long long
using namespace std;
vector<int> adj[100005];
vector<pair<int,int>> ans;
int low[100005],depths[100005];
void dfs(int cur,int par){
depths[cur] = depths[par] + 1;
low[cur] = depths[cur];
// cout << 1;
for (auto it : adj[cur]){
if (it!=par){
if (depths[it]==-1){
dfs(it,cur);
low[cur] = min(low[cur],low[it]);
if (low[it]>depths[cur]){
ans.push_back(make_pair(it,cur));
}
}else{
low[cur] = min(low[cur],depths[it]);
}
}
}
}
int32_t main(){
ios_base::sync_with_stdio(0);cin.tie(0);
int n,m;cin>>n>>m;
fill(depths,depths+100005,-1);
// cout << depths[1];
for (int i=0;i<m;++i){
int a,b;cin>>a>>b;
adj[a].push_back(b);
adj[b].push_back(a);
}
for (int i=1;i<=n;++i){
if (depths[x]==-1)dfs(i,i);
}
for (auto it:ans){
int a = it.first, b= it.second;
if (a<b) swap(a,b);
cout << b << " " << a << '\n';
}
}
Compilation message
pipes.cpp: In function 'int32_t main()':
pipes.cpp:40:20: error: 'x' was not declared in this scope
40 | if (depths[x]==-1)dfs(i,i);
| ^
