#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/trie_policy.hpp>
#define pb push_back
#define mp make_pair
#define taskname "A"
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
typedef tree <int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
const int maxn = 1e5 + 5;
const int logn = log2(maxn) + 1;
int n , m , nEdge = 0;
int P[maxn][logn];
int lab[maxn] , h[maxn] , dp[maxn];
vector<int> adj[maxn];
int FindLab(int u){
return lab[u] < 0 ? u : lab[u] = FindLab(lab[u]);
}
void BuildLCA(int u , int par){
P[u][0] = par;
for(int i = 1 ; i < logn && P[u][i - 1] ; ++i){
P[u][i] = P[P[u][i - 1]][i - 1];
}
}
void dfs(int u , int par){
for(int c : adj[u]){
if(par != c){
h[c] = h[u] + 1;
BuildLCA(c , u);
dfs(c , u);
}
}
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
if(fopen(taskname".INP","r")){
freopen(taskname".INP", "r",stdin);
freopen(taskname".OUT", "w",stdout);
}
fill_n(lab,maxn,-1);
cin >> n >> m;
for(int u , v , s , t , i = 1 ; i <= m ; ++i){
cin >> u >> v;
s = FindLab(u);
t = FindLab(v);
if(s != t){
if(lab[s] > lab[t])swap(s , t) , swap(u , v);
lab[s] += lab[t];
lab[t] = s;
adj[u].pb(v);
adj[v].pb(u);
}
}
for(int i = 1 ; i <= n ; ++i){
if(h[i] == 0){
h[i] = 1;
dfs(i , 0);
}
}
fill_n(lab,maxn,-1);
rewind(stdin);
cin >> n >> m;
for(int u , v , s , t , i = 1 ; i <= m ; ++i){
cin >> u >> v;
s = FindLab(u);
t = FindLab(v);
if(s != t){
if(lab[s] > lab[t])swap(s , t) , swap(u , v);
lab[s] += lab[t];
lab[t] = s;
}else{
auto lca = [&](int &u , int &v){
if(h[u] < h[v])swap(u , v);
for(int i = 0 ; i < logn && h[u] != h[v] ; ++i){
if((h[u] - h[v]) & (1 << i))u = P[u][i];
}
if(u == v)return u;
for(int i = logn - 1 ; i >= 0 ; --i){
if(P[u][i] != P[v][i])u = P[u][i] , v = P[v][i];
}
return P[u][0];
};
dp[u]++;dp[v]++;
dp[lca(u,v)] -= 2;
}
}
fill_n(h,maxn,0);
for(int i = 1 ; i <= n ; ++i){
if(h[i] == 0){
h[i] = 1;
function<void(int&,int&)> dfs = [&](int& u , int &par){
for(int v : adj[u]){
if(v != par){
h[v] = h[u] + 1;
dfs(v , u);
dp[u] += dp[v];
if(dp[v] == 0)cout << u << " " << v << '\n';
}
}
};
dfs(i , i);
}
}
}
Compilation message
pipes.cpp: In function 'int main()':
pipes.cpp:51:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen(taskname".INP", "r",stdin);
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
pipes.cpp:52:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen(taskname".OUT", "w",stdout);
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
3448 KB |
Output is correct |
2 |
Correct |
5 ms |
3576 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
13 ms |
4088 KB |
Output is correct |
2 |
Correct |
13 ms |
3960 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
347 ms |
3916 KB |
Output is correct |
2 |
Correct |
332 ms |
3912 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
631 ms |
4516 KB |
Output is correct |
2 |
Correct |
723 ms |
4344 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1075 ms |
6148 KB |
Output is correct |
2 |
Correct |
875 ms |
6612 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1552 ms |
10780 KB |
Output is correct |
2 |
Correct |
1385 ms |
10512 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2473 ms |
11752 KB |
Output is correct |
2 |
Correct |
2253 ms |
11548 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3583 ms |
13944 KB |
Output is correct |
2 |
Correct |
3313 ms |
13652 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4484 ms |
13956 KB |
Output is correct |
2 |
Correct |
4261 ms |
13788 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Execution timed out |
5043 ms |
13528 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |