#include<bits/stdc++.h>
#include<fstream>
using namespace std;
ifstream fin("HCN.INP");
ofstream fout("HCN.OUT");
#define sz(a) (int)a.size()
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
const ld PI = 3.14159265359;
//using u128 = __uint128_t;
//const int x[4] = {1, -1, 0, 0};
//const int y[4] = {0, 0, 1, -1};
const ll mod = 1e9 + 9;
const int mxn = 1e5 + 5, mxq = 2e5 + 5, sq = 200, mxv = 2e6 + 5;
const ll inf = 1e17 + 5;
//const int base= (1 << 18);
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
int n, m;
struct DSU{
int pa[mxn + 1];
int fp(int u){
if(pa[u] < 0)return(u);
return(pa[u] = fp(pa[u]));
}
bool unon(int u, int v){
u = fp(u); v = fp(v);
if(u == v)return(0);
if(abs(pa[u]) < abs(pa[v]))swap(u, v);
pa[u] += pa[v]; pa[v] = u;
return(1);
}
void init(){
for(int i = 1; i <= n; i++)pa[i] = -1;
}
};
DSU norma, cool;
vt<pii>adj[mxn + 1];
vt<pii>res;
int num[mxn + 1], low[mxn + 1], tt = 0;
bool used[mxn + 1];
void dfs(int s){
num[s] = low[s] = ++tt;
for(auto [v, id]: adj[s]){
if(used[id])continue;
used[id] = 1;
if(!num[v]){
dfs(v);
if(low[v] > num[s]){
res.pb({s, v});
}
low[s] = min(low[s], low[v]);
}else{
low[s] = min(low[s], num[v]);
}
}
}
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m;
norma.init(); cool.init();
int id = 0;
for(int i = 0; i < m; i++){
int u, v; cin >> u >> v;
if(norma.unon(u, v)){
id++;
adj[u].pb({v, id}); adj[v].pb({u, id});
}else if(cool.unon(u, v)){
id++;
adj[u].pb({v, id}); adj[v].pb({u, id});
}
}
assert(id <= 2 * n);
for(int i = 1; i <= n; i++){
if(!num[i]){
dfs(i);
}
}
for(auto [u, v]: res)cout << u << ' ' << v << "\n";
return(0);
}
Compilation message
pipes.cpp: In function 'void dfs(int)':
pipes.cpp:52:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
52 | for(auto [v, id]: adj[s]){
| ^
pipes.cpp: In function 'int main()':
pipes.cpp:89:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
89 | for(auto [u, v]: res)cout << u << ' ' << v << "\n";
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
3420 KB |
Output is correct |
2 |
Correct |
1 ms |
3420 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
3932 KB |
Output is correct |
2 |
Correct |
3 ms |
3676 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
65 ms |
3760 KB |
Output is correct |
2 |
Correct |
71 ms |
3672 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
109 ms |
4704 KB |
Output is correct |
2 |
Correct |
127 ms |
4184 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
192 ms |
6484 KB |
Output is correct |
2 |
Runtime error |
187 ms |
19968 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
248 ms |
12288 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
408 ms |
13604 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
485 ms |
15884 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
597 ms |
21292 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
817 ms |
33924 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |