#include <bits/stdc++.h>
using namespace std;
using vi = vector <int>;
using uc = unsigned char;
const int MAXN = 8E4;
vector <uc> adj1[MAXN];
vector <bool> adj2[MAXN];
bitset <MAXN> vis1, vis2;
int tin[MAXN], fup[MAXN], timer = 0;
uc f1 (int x) { return x&0xff; }
uc f2 (int x) { return x>>8&0xff; }
bool f3 (int x) { return x>>16&1; }
int frec (uc v1, uc v2, bool v3) { return int(v1)|int(v2)<<8|int(v3)<<16; }
void dfs (int u, int par) {
vis1[u] = true;
fup[u] = tin[u] = timer++;
for (int i = 0; i < adj1[u].size(); i += 2) {
int v = frec(adj1[u][i], adj1[u][i+1], adj2[u][i>>1]);
if (v == par) { par = u; continue; }
if (vis2[v]) continue;
if (vis1[v]) {
fup[u] = min(fup[u], tin[v]);
} else {
dfs(v, u);
fup[u] = min(fup[u], fup[v]);
if (fup[v] == tin[v]) { // bridge (u, v)
cout << u+1 << ' ' << v+1 << '\n';
}
}
}
vis2[u] = true;
}
int main () {
cin.tie(nullptr) -> sync_with_stdio(false);
int n, m;
cin >> n >> m;
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
u--; v--;
adj1[u].push_back(f1(v));
adj1[u].push_back(f2(v));
adj2[u].push_back(f3(v));
adj1[v].push_back(f1(u));
adj1[v].push_back(f2(u));
adj2[v].push_back(f3(u));
}
for (int u = 0; u < n; u++) {
if (vis2[u]) continue;
dfs(u, u);
}
return 0;
}
Compilation message
pipes.cpp: In function 'void dfs(int, int)':
pipes.cpp:20:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<unsigned char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
20 | for (int i = 0; i < adj1[u].size(); i += 2) {
| ~~^~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
5724 KB |
Output is correct |
2 |
Correct |
1 ms |
5724 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
6608 KB |
Output is correct |
2 |
Correct |
3 ms |
6236 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
71 ms |
10456 KB |
Output is correct |
2 |
Correct |
69 ms |
15392 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
129 ms |
13140 KB |
Output is correct |
2 |
Runtime error |
160 ms |
25988 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
211 ms |
20564 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
297 ms |
29572 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
502 ms |
53328 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
5 ms |
11608 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
7 ms |
11616 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
4 ms |
11612 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |