/**
* Sources: various
*/
#pragma GCC optimize("O3")
#pragma GCC target("sse4")
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
const int MOD = 1000000007;
template<typename T>
ostream& operator<< (ostream& out, const pair<T, T>& v) {
out << "{" << v.first << ", " << v.second << "}";
return out;
}
template<typename T>
ostream& operator<< (ostream& out, const vector<T>& v) {
out << "[";
size_t last = v.size() - 1;
for(size_t i = 0; i < v.size(); ++i) {
out << v[i];
if (i != last)
out << ", ";
}
out << "]";
return out;
}
template<typename T>
ostream& operator<< (ostream& out, const set<T>& v) {
out << "[";
auto pen = v.end();
pen--;
for (auto it = v.begin(); it != v.end(); it++){
out << *it;
if (it != pen){
out << ", ";
}
}
out << "]";
return out;
}
template<typename T>
ostream& operator<< (ostream& out, const Tree<T>& v) {
out << "[";
auto pen = v.end();
pen--;
for (auto it = v.begin(); it != v.end(); it++){
out << *it;
if (it != pen){
out << ", ";
}
}
out << "]";
return out;
}
template<int SZ> struct DSU {
int par[SZ];
DSU() {
F0R(i,SZ) par[i] = i;
}
int get(int x) { // path compression
if (par[x] != x) par[x] = get(par[x]);
return par[x];
}
bool unite(int x, int y) { // union-by-rank
x = get(x), y = get(y);
if (x == y) return 0;
par[y] = x;
return 1;
}
};
DSU<100005> one_connected;
DSU<100005> two_connected;
vector<int> adj[100005];
int timer = 1;
int ti[100005]; int fup[100005];
bool vis[100005];
void DFS(int v, int p = -1){
if (vis[v]) return;
vis[v] = true;
ti[v] = fup[v] = timer++;
//cout << v << ' ' << timer << endl;
for (int j: adj[v]){
if (j == p) continue;
if (vis[j]){
assert(ti[j] != -1);
fup[v] = min(ti[j], fup[v]);
}
else{
DFS(j, v);
fup[v] = min(fup[j], fup[v]);
if (fup[j] > ti[v]){
cout << v << ' ' << j << endl;
}
}
}
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(0);
int n, m; cin >> n >> m;
int u, v;
for (int i = 1; i <= n; i++){
ti[i] = -1; fup[i] = -1;
}
for (int i = 0; i < m; i++){
cin >> u >> v;
if (!one_connected.unite(u, v)){
if (!two_connected.unite(u, v)){
continue;
}
else{
adj[u].pb(v);
adj[v].pb(u);
}
}
else{
adj[u].pb(v);
adj[v].pb(u);
}
}
for (int i = 1; i <= n; i++){
if (!vis[i]){
DFS(i);
}
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
3456 KB |
Output is correct |
2 |
Incorrect |
4 ms |
3456 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
3968 KB |
Output is correct |
2 |
Incorrect |
8 ms |
3712 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
95 ms |
3832 KB |
Output is correct |
2 |
Incorrect |
94 ms |
3692 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
158 ms |
4504 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
284 ms |
6084 KB |
Output is correct |
2 |
Correct |
252 ms |
5544 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
463 ms |
11000 KB |
Output is correct |
2 |
Incorrect |
361 ms |
7416 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
629 ms |
12020 KB |
Output is correct |
2 |
Incorrect |
622 ms |
9260 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
838 ms |
14064 KB |
Output is correct |
2 |
Incorrect |
835 ms |
9256 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1096 ms |
14060 KB |
Output is correct |
2 |
Incorrect |
1030 ms |
9216 KB |
Wrong number of edges |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1292 ms |
13568 KB |
Output is correct |
2 |
Correct |
1228 ms |
10756 KB |
Output is correct |