#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,sse3,sse4,popcnt,abm,mmx")
#include <bits/stdc++.h>
#include <stdio.h>
using namespace std;
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define pf push_front
#define ppb pop_back
#define mp make_pair
#define bpp __builtin_popcount
#define sqr(x) ((x) * (x))
#define al 0x3F3F3F3F
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define in insert
#define ppf pop_front
#define endl '\n'
//#define int long long
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef pair <int, int> pii;
const int mod = (int)1e9 + 7;
const int N = (int)3e4 + 123;
const ll inf = (ll)3e18 + 1;
const double pi = acos(-1.0);
const double eps = 1e-7;
const int dx[] = {0, 0, 1, 0, -1};
const int dy[] = {0, 1, 0, -1, 0};
int n, m, tin[N], fup[N], timer;
bool used[N];
int u[N * 10];
set <pii> ans;
vector <int> g[N];
void dfs (int v, int p = 0) {
used[v] = 1;
tin[v] = fup[v] = ++ timer;
int ok = 0;
for (auto to : g[v]) {
if (to == p) {
if (!ok) {
ok ++;
continue;
}
}
if (used[to]) fup[v] = min (fup[v], tin[to]);
else {
dfs (to, v);
fup[v] = min (fup[v], fup[to]);
if (fup[to] > tin[v]) ans.in ({min (v, to), max (v, to)});
}
}
}
inline void boost () {
ios_base :: sync_with_stdio (NULL);
cin.tie (NULL), cout.tie (NULL);
}
inline void Solve () {
cin >> n >> m;
bool ch = (m >= 600000);
while (m --) {
int x, y;
cin >> x >> y;
if (x == y) continue;
if (ch) {
if (u[x * 10 + y] == 2 || u[y * 10 + x] == 2) continue;
u[x * 10 + y] ++;
u[y * 10 + x] ++;
}
g[x].pb (y);
g[y].pb (x);
}
for (int i = 1; i <= n; i ++)
if (!used[i])
dfs (i);
for (auto to : ans)
cout << to.F << ' ' << to.S << endl;
}
main () {
// freopen ("gcm.in", "r", stdin);
// freopen ("gcm.out", "w", stdout);
boost ();
int tt = 1;
// cin >> tt;
while (tt --) {
Solve ();
}
return 0;
}
Compilation message
pipes.cpp:94:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main () {
^
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
1024 KB |
Output is correct |
| 2 |
Correct |
3 ms |
1024 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
6 ms |
1664 KB |
Output is correct |
| 2 |
Correct |
5 ms |
1408 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
137 ms |
9268 KB |
Output is correct |
| 2 |
Correct |
136 ms |
8580 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
180 ms |
3960 KB |
Output is correct |
| 2 |
Correct |
209 ms |
3164 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
359 ms |
8108 KB |
Output is correct |
| 2 |
Incorrect |
367 ms |
7960 KB |
Wrong number of edges |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
3 ms |
1920 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
5 ms |
1920 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
4 ms |
1968 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
4 ms |
1920 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
4 ms |
1920 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
