#include <bits/stdc++.h>
using namespace std;
#define rep(i, a, b) for (int i = (a); i < (b); ++i)
#define per(i, a, b) for (int i = (b - 1); i >= (a); --i)
#define trav(a, x) for (auto &a : x)
#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define pb push_back
#define debug(x) cout << #x << " = " << x << endl
#define umap unordered_map
#define uset unordered_set
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<pll> vpll;
const int INF = 1'000'000'007;
struct union_find {
int p[100001], rank[100001];
union_find(int n) {
rep(i, 0, n) p[i] = i;
memset(rank, 0, n * 4);
}
int find_set(int i) { return p[i] == i ? i : p[i] = find_set(p[i]); }
bool union_set(int i, int j) {
i = find_set(i);
j = find_set(j);
if (i == j) return 0;
if (rank[i] < rank[j]) swap(i, j);
if (rank[i] == rank[j]) ++rank[i];
p[j] = i;
return 1;
}
};
int dfs_p[100001], dfs_num[100001], dfs_lo[100001],cnt=0;
vi graph[100001];
void dfs(int u){
dfs_num[u]=dfs_lo[u]=cnt++;
trav(v,graph[u]) if(v!=dfs_p[u]){
if(dfs_num[v]==-1){
dfs_p[v]=u;
dfs(v);
if(dfs_num[u]<dfs_lo[v])cout<<u+1<<' '<<v+1<<endl;
dfs_lo[u]=min(dfs_lo[u],dfs_lo[v]);
}
else dfs_lo[u] = min(dfs_lo[u], dfs_num[v]);
}
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
memset(dfs_num,-1,sizeof(dfs_num));
int n, m, u, v;
cin >> n >> m;
union_find uf1(n), uf2(n);
rep(i, 0, m) {
cin >> u >> v;
--u;
--v;
if (!uf1.union_set(u, v)) {
if (uf2.union_set(u, v)) {
graph[u].pb(v);
graph[v].pb(u);
}
} else {
graph[u].pb(v);
graph[v].pb(u);
}
}
rep(i,0,n){
if(dfs_num[i]!=-1)continue;
cnt=0;
dfs_p[i]=i;
dfs(i);
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4556 KB |
Output is correct |
2 |
Incorrect |
3 ms |
4556 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
5148 KB |
Output is correct |
2 |
Incorrect |
6 ms |
4940 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
90 ms |
10368 KB |
Output is correct |
2 |
Incorrect |
110 ms |
10104 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
186 ms |
15220 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
295 ms |
16176 KB |
Output is correct |
2 |
Runtime error |
221 ms |
20708 KB |
Memory limit exceeded |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
335 ms |
13168 KB |
Output is correct |
2 |
Incorrect |
319 ms |
9748 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
546 ms |
14520 KB |
Output is correct |
2 |
Incorrect |
559 ms |
11972 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
823 ms |
17508 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
877 ms |
17440 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
986 ms |
21712 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |