#include <bits/stdc++.h>
using namespace std;
#define ll int
#define ii pair<ll,ll>
#define endl '\n'
const ll inf=1e15;
const ll mod=1e9+7;
const ll maxn=1e5+5;
vector<ll> adj[maxn];
ll cnt[maxn],depth[maxn],low[maxn];
ll par[maxn][2];
int root(ll x, ll l){
if (par[x][l]==x) return x;
return par[x][l]=root(par[x][l],l);
}
bool connect(ll a, ll b, ll l){
if (root(a,l)==root(b,l)) return 0;
par[root(a,l)][l]=root(b,l);
return 1;
}
void dfs(ll node, ll p){
bool seen=0;
for (auto &u:adj[node]){
if (u==p && !seen){
seen=1;
continue;
}
if (!depth[u]){
depth[u]=depth[node]+1;
dfs(u,node);
if (low[u]>depth[node]){
cout<<node<<' '<<u<<endl;
}
low[node]=min(low[node],low[u]);
} else{
low[node]=min(low[node],depth[u]);
}
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
ll n,e,a,b;
cin>>n>>e;
for (int i=0;i<maxn;i++) low[i]=inf;
for (int i=0;i<maxn;i++){
par[i][0]=i;
par[i][1]=i;
}
for (int i=0;i<e;i++){
cin>>a>>b;
if (connect(a,b,0) || connect(a,b,1)){
adj[a].emplace_back(b);
adj[b].emplace_back(a);
}
}
for (int i=1;i<=n;i++){
if (depth[i]) continue;
depth[i]=1;
dfs(i,-1);
}
return 0;
}
Compilation message
pipes.cpp:7:14: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+15' to '2147483647' [-Woverflow]
7 | const ll inf=1e15;
| ^~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
3788 KB |
Output is correct |
2 |
Correct |
2 ms |
3788 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
4300 KB |
Output is correct |
2 |
Correct |
7 ms |
4044 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
83 ms |
4116 KB |
Output is correct |
2 |
Correct |
84 ms |
3968 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
146 ms |
4804 KB |
Output is correct |
2 |
Correct |
166 ms |
4652 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
278 ms |
6452 KB |
Output is correct |
2 |
Correct |
201 ms |
5848 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
338 ms |
11752 KB |
Output is correct |
2 |
Correct |
291 ms |
7552 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
497 ms |
12712 KB |
Output is correct |
2 |
Correct |
486 ms |
9480 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
679 ms |
14876 KB |
Output is correct |
2 |
Correct |
617 ms |
9144 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
839 ms |
14872 KB |
Output is correct |
2 |
Correct |
859 ms |
9124 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1014 ms |
14284 KB |
Output is correct |
2 |
Correct |
915 ms |
11052 KB |
Output is correct |