#include <bits/stdc++.h>
#define N 100005
using namespace std;
int par[N][2];
int find(int a,int val){
if(par[a][val] == a)return a;
return par[a][val] = find(par[a][val],val);
}
vector<int> adj[N];
map<pair<int,int>,int> mp;
bool merge(int a,int b,int val){
int tmp1 = a,tmp2 = b;
a = find(a,val);
b = find(b,val);
if(a == b)return 0;
par[a][val] = b;
adj[tmp1].push_back(tmp2);
adj[tmp2].push_back(tmp1);
if(val){
mp[{tmp1,tmp2}] = 1;
mp[{tmp2,tmp1}] = 1;
}
return 1;
}
int n;
vector<bool> visited;
vector<int> tin, low;
int timer;
void IS_BRIDGE(int v,int a){
if(!mp[{v,a}])
cout << v << " " << a << endl;
}
void dfs(int v, int p = -1) {
visited[v] = true;
tin[v] = low[v] = timer++;
for (int to : adj[v]) {
if (to == p) continue;
if (visited[to]) {
low[v] = min(low[v], tin[to]);
} else {
dfs(to, v);
low[v] = min(low[v], low[to]);
if (low[to] > tin[v])
IS_BRIDGE(v, to);
}
}
}
void find_bridges() {
timer = 0;
visited.assign(N, false);
tin.assign(N, -1);
low.assign(N, -1);
for (int i = 1; i <= n; ++i) {
if (!visited[i])
dfs(i);
}
}
void solve(){
int m;
cin >> n >> m;
for(int i=1;i<=n;i++){
par[i][0] = par[i][1] = i;
}
int l,r;
for(int i=1;i<=m;i++){
cin >> l >> r;
if(!merge(l,r,0))
merge(l,r,1);
}
find_bridges();
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#ifdef Local
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t=1;
//cin>>t;
while(t--){
solve();
}
#ifdef Local
cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
#endif
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
3436 KB |
Output is correct |
2 |
Correct |
3 ms |
3436 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
4460 KB |
Output is correct |
2 |
Correct |
10 ms |
4204 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
116 ms |
4332 KB |
Output is correct |
2 |
Correct |
111 ms |
4076 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
200 ms |
5564 KB |
Output is correct |
2 |
Runtime error |
240 ms |
16492 KB |
Memory limit exceeded |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
351 ms |
8752 KB |
Output is correct |
2 |
Correct |
291 ms |
7356 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
567 ms |
18948 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
888 ms |
21228 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1117 ms |
25452 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1338 ms |
25452 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1592 ms |
24228 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |