#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 500007;
const ll inf = 1e18;
const ll mod = 1e9+7;
const double pi = acos(-1);
const int dx[] = {0, -1, 0, 1}, dy[] = {1, 0, -1, 0};
const int block = 320;
int n;
vector <int> v, adj[M];
int main(){
cin >> n;
for(int i = 1; i < n; ++i){
int a, b;
cin >> a >> b;
adj[a].pb(b);
adj[b].pb(a);
}
for(int i = 1; i <= n; ++i) if(adj[i].size() == 1) v.pb(i);
cout << ((int)v.size() + 1) / 2 << endl;
for(int i = 0; i < (int)v.size() - 1; i += 2) cout << v[i] << " " << v[i + 1] << endl;
if((int)v.size() % 2) cout << v.back() << " " << v[0] << endl;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
11980 KB |
Output is correct |
2 |
Correct |
7 ms |
11980 KB |
Output is correct |
3 |
Correct |
6 ms |
11980 KB |
Output is correct |
4 |
Correct |
7 ms |
11980 KB |
Output is correct |
5 |
Correct |
6 ms |
11980 KB |
Output is correct |
6 |
Correct |
7 ms |
11980 KB |
Output is correct |
7 |
Correct |
8 ms |
12016 KB |
Output is correct |
8 |
Correct |
7 ms |
11948 KB |
Output is correct |
9 |
Correct |
6 ms |
11980 KB |
Output is correct |
10 |
Incorrect |
9 ms |
12004 KB |
Breaking single line is causing network to disconnect. |
11 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
11980 KB |
Output is correct |
2 |
Correct |
7 ms |
11980 KB |
Output is correct |
3 |
Correct |
6 ms |
11980 KB |
Output is correct |
4 |
Correct |
7 ms |
11980 KB |
Output is correct |
5 |
Correct |
6 ms |
11980 KB |
Output is correct |
6 |
Correct |
7 ms |
11980 KB |
Output is correct |
7 |
Correct |
8 ms |
12016 KB |
Output is correct |
8 |
Correct |
7 ms |
11948 KB |
Output is correct |
9 |
Correct |
6 ms |
11980 KB |
Output is correct |
10 |
Incorrect |
9 ms |
12004 KB |
Breaking single line is causing network to disconnect. |
11 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
11980 KB |
Output is correct |
2 |
Correct |
7 ms |
11980 KB |
Output is correct |
3 |
Correct |
6 ms |
11980 KB |
Output is correct |
4 |
Correct |
7 ms |
11980 KB |
Output is correct |
5 |
Correct |
6 ms |
11980 KB |
Output is correct |
6 |
Correct |
7 ms |
11980 KB |
Output is correct |
7 |
Correct |
8 ms |
12016 KB |
Output is correct |
8 |
Correct |
7 ms |
11948 KB |
Output is correct |
9 |
Correct |
6 ms |
11980 KB |
Output is correct |
10 |
Incorrect |
9 ms |
12004 KB |
Breaking single line is causing network to disconnect. |
11 |
Halted |
0 ms |
0 KB |
- |