#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define f(i,a,b) for( ll i = a; i < b ; i++ )
#define af(i,a,b) for( ll i = a; i >= b ; i--)
#define rep(i,a,b,k) for(ll i = a; i < b ; i+= k )
#define arep(i,a,b,k) for( ll i = a; i >= b ; i-= k)
#define ones(ini) (ll) __builtin_popcountll(x)
#define todo(y,val) all_of(all(y),[&val](ll x) {return (x == ((ll)val));})
#define nada(y,val) none_of(all(y),[&val](ll x) {return (x == ((ll)val));})
#define algu(y,val) any_of(all(y),[&val](ll x) {return (x == ((ll)val));})
#define cuantos(a,x) count(all(a),x)
#define fs first
#define sc second
#define pb push_back
#define po pop_back
#define sz(a) (ll) a.size()
#define all(a) a.begin(), a.end()
#define sor(a) sort( a.begin(), a.end() )
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ller ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr)
#define watch(x) cout << (#x) << " is " << (x) <<"\n"
#define test ll deftestcases;cin>>deftestcases;while(deftestcases--)
#define PI acos(-1)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;
template<class T> using ordered_set =tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update> ;
const ll inf = 2e18;
const ll mod = 1e9+7;
const ll MAX = 2e5+10;
vi adj[MAX];
ll dspar[2][MAX];
bool vis[MAX];
ll tin[MAX],low[MAX];
vii ans;
ll timer = 0;
ll finds(ll aux,ll v){
if(v == dspar[aux][v]) return v;
return dspar[aux][v] = finds(aux,dspar[aux][v]);
}
bool uni(ll aux,ll a,ll b){
ll u = a,v = b;
a = finds(aux,a),b = finds(aux,b);
if(a==b) return 0;
dspar[aux][b] = a;
adj[u].pb(v);
adj[v].pb(u);
return 1;
}
void is_bridge(ll u,ll v){
ans.pb({u,v});
}
bool check(ll u,ll v){
return finds(1,u)==finds(1,v);
}
void dfs(ll u,ll par = -1){
vis[u] = 1;
tin[u] = low[u] = timer++;
for(auto v : adj[u]){
if(v == par) continue;
if(vis[v]) low[u] = min(low[u],tin[v]);
else{
dfs(v,u);
if(low[v] >tin[u] && !(check(u,v))) is_bridge(u,v);
low[u] = min(low[u],low[v]);
}
}
}
void init_bridges(ll n,ll m){
timer = 0;
f(i,0,n+1){
tin[i]=low[i]=-1;
dspar[0][i] = dspar[1][i] = i;
}
f(i,0,m){
ll u,v;cin>>u>>v;
if(!uni(0,u,v)){
uni(1,u,v);
}
}
f(i,1,n+1){
if(!vis[i]) dfs(i);
}
}
void print_bridges(){
for(auto it : ans){
cout<<it.fs<<" "<<it.sc<<"\n";
}
}
int main(){
fastio;
timer = 0;
ll n,m;cin>>n>>m;
init_bridges(n,m);
print_bridges();
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
4940 KB |
Output is correct |
2 |
Correct |
3 ms |
4940 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
9 ms |
5708 KB |
Output is correct |
2 |
Correct |
7 ms |
5452 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
111 ms |
5508 KB |
Output is correct |
2 |
Correct |
114 ms |
9028 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
190 ms |
6644 KB |
Output is correct |
2 |
Correct |
228 ms |
9620 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
329 ms |
8732 KB |
Output is correct |
2 |
Correct |
335 ms |
12504 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
456 ms |
16156 KB |
Output is correct |
2 |
Correct |
405 ms |
13548 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
711 ms |
21456 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
934 ms |
24580 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1138 ms |
24548 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1347 ms |
20420 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |