#include <bits/stdc++.h>
#define F first
#define S second
#define mp make_pair
#define pb push_back
#define ll long long
#define LEFT(a) ((a)<<1)
#define RIGHT(a) (LEFT(a) + 1)
#define MID(a,b) ((a+b)>>1)
#define MAX(a,b) ((a)>(b)?(a):(b))
#define MIN(a,b) ((a)<(b)?(a):(b))
//#pragma comment(linker, "/STACK: 20000000005")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx2,fma")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
using namespace std;
const int N = 1e5 + 5, M = 6e6 + 5;
int n, m;
int nn, u[N], v[N];
vector < int > g[N];
int T;
int in[N], up[N];
void dfs (int k, int p){
in[k] = ++T;
up[k] = in[k];
int to;
for (int toto : g[k]){
to = abs (toto);
if (to == p)
continue;
if (in[to]){
up[k] = min (up[k], in[to]);
continue;
}
dfs (to, k);
if (up[to] > in[k] && toto > 0){
nn++;
u[nn] = k;
v[nn] = to;
}
up[k] = min (up[k], up[to]);
}
}
pair < int, int > P[M];
main()
{
//freopen ("in.in", "r", stdin);freopen ("out.out", "w", stdout);
//ios_base::sync_with_stdio(false);
cin >> n >> m;
for (int i = 1; i <= m; i++){
scanf ("%d %d", &P[i].F, &P[i].S);
}
sort (P + 1, P + m + 1);
for (int i = 1; i <= m; i++){
if (P[i] == P[i - 1])
continue;
if (P[i + 1] != P[i]){
g[P[i].F].pb (P[i].S);
g[P[i].S].pb (P[i].F);
}
else {
g[P[i].F].pb (-P[i].S);
g[P[i].S].pb (-P[i].F);
}
}
for (int i = 1; i <= n; i++)
if (in[i] == 0)
dfs (i, 0);
for (int i = 1; i <= nn; i++)
cout << u[i] << " " << v[i] << endl;
return 0;
}
Compilation message
pipes.cpp:17:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
#pragma GCC optimization ("O3")
pipes.cpp:18:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
#pragma GCC optimization ("unroll-loops")
pipes.cpp:55:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main()
^
pipes.cpp: In function 'int main()':
pipes.cpp:61:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf ("%d %d", &P[i].F, &P[i].S);
~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
2680 KB |
Output is correct |
2 |
Correct |
5 ms |
2680 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
11 ms |
3192 KB |
Output is correct |
2 |
Correct |
11 ms |
3064 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
252 ms |
15200 KB |
Output is correct |
2 |
Correct |
245 ms |
14712 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
424 ms |
21368 KB |
Memory limit exceeded (if you are sure your verdict is not MLE, please contact us) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
691 ms |
35292 KB |
Memory limit exceeded (if you are sure your verdict is not MLE, please contact us) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
982 ms |
41124 KB |
Memory limit exceeded (if you are sure your verdict is not MLE, please contact us) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1491 ms |
65540 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1890 ms |
65540 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
2207 ms |
65540 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
2551 ms |
65540 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |