#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int par1[N], par2[N], h[N], mnh[N], edges;
bool vis[N];
vector<pair<int, int>> g[N];
int root1(int v){
return (par1[v] == -1 ? v : par1[v] = root1(par1[v]));
}
int root2(int v){
return (par2[v] == -1 ? v : par2[v] = root2(par2[v]));
}
void merge1(int u, int v){
int r1 = root1(v);
int r2 = root1(u);
par1[r1] = r2;
edges++;
g[v].push_back({u, edges});
g[u].push_back({v, edges});
}
void merge2(int u, int v){
int r1 = root2(u);
int r2 = root2(v);
if (r1 == r2)
return;
par2[r1] = r2;
edges++;
g[v].push_back({u, edges});
g[u].push_back({v, edges});
}
void dfs(int v, pair<int, int> prev = {-1, -1}){
vis[v] = 1;
if (prev.first == -1)
h[v] = 0;
mnh[v] = h[v];
for (auto [u, id] : g[v]){
if (prev.first == u and prev.second == id)
continue;
mnh[v] = min(mnh[v], h[u]);
if (vis[u])
continue;
h[u] = h[v] + 1;
dfs(u, {v, id});
mnh[v] = min(mnh[v], mnh[u]);
if (mnh[u] >= h[u])
printf("%d%d\n", u, v);
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, m;
scanf("%d%d", &n, &m);
for (int i=1; i<=n; i++){
par1[i] = par2[i] = -1;
mnh[i] = n + 100;
h[i] = n + 100;
}
for (int i=0; i<m; i++){
int u, v;
scanf("%d%d", &u, &v);
if (root1(u) != root1(v))
merge1(u, v);
else if (root2(u) != root2(v))
merge2(u, v);
}
for (int v = 1; v <= n; v++)
if (!vis[v])
dfs(v);
}
Compilation message
pipes.cpp: In function 'int main()':
pipes.cpp:72:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
72 | scanf("%d%d", &n, &m);
| ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:82:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
82 | scanf("%d%d", &u, &v);
| ~~~~~^~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2648 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
4 ms |
3420 KB |
Wrong number of edges |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
80 ms |
3080 KB |
Output is correct |
2 |
Incorrect |
70 ms |
2904 KB |
Wrong number of edges |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
126 ms |
3920 KB |
Output is correct |
2 |
Incorrect |
138 ms |
3556 KB |
Wrong number of edges |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
207 ms |
5896 KB |
Output is correct |
2 |
Incorrect |
186 ms |
5364 KB |
Expected int32, but "2924129240" found |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
269 ms |
12188 KB |
Output is correct |
2 |
Runtime error |
245 ms |
26760 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
414 ms |
13580 KB |
Output is correct |
2 |
Runtime error |
408 ms |
42960 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
546 ms |
16212 KB |
Output is correct |
2 |
Runtime error |
571 ms |
52476 KB |
Memory limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
682 ms |
22368 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
814 ms |
34524 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |