//雪花飄飄北風嘯嘯
//天地一片蒼茫
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl;
#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()
ll MAX(ll a){return a;}
ll MIN(ll a){return a;}
template<typename... Args>
ll MAX(ll a,Args... args){return max(a,MAX(args...));}
template<typename... Args>
ll MIN(ll a,Args... args){return min(a,MIN(args...));}
#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
int n,m;
ii al[12000005];
int pp[100005];
int dfs_time[100005]; ///first time to reach vertex
int low[100005]; ///lowest time vertex it can reach with 1 backtrack
int dfs_counter=1;
void dfs(int i,int j){ ///j is parent of i
dfs_time[i]=low[i]=dfs_counter++;
bool vis_par=false;
rep(x,pp[i],pp[i+1]){
int it=al[x].se;
if (!dfs_time[it]){ ///uninitialized vertex
dfs(it,i);
low[i]=min(low[i],low[it]);
if (low[it]>dfs_time[i]){
cout<<it<<" "<<i<<endl;
}
}
else if (it!=j || vis_par){ ///make sure it is a back edge
low[i]=min(low[i],dfs_time[it]);
}
else{
vis_par=true;
}
}
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin>>n>>m;
int a,b;
rep(x,0,m){
cin>>a>>b;
al[2*x]={a,b};
al[2*x+1]={b,a};
}
sort(al,al+2*m);
rep(x,2*m,0) pp[al[x].fi]=x;
pp[n+1]=2*m;
rep(x,1,n+1) if (!dfs_time[x]) dfs(x,-1);
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
384 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
12 ms |
1024 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
262 ms |
19448 KB |
Memory limit exceeded (if you are sure your verdict is not MLE, please contact us) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
446 ms |
32936 KB |
Memory limit exceeded (if you are sure your verdict is not MLE, please contact us) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
710 ms |
49784 KB |
Memory limit exceeded (if you are sure your verdict is not MLE, please contact us) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
896 ms |
64248 KB |
Memory limit exceeded (if you are sure your verdict is not MLE, please contact us) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
468 ms |
65540 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
480 ms |
65536 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
479 ms |
65540 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
458 ms |
65536 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |