# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
108708 |
2019-05-01T06:10:33 Z |
Mahdi_Jfri |
Network (BOI15_net) |
C++14 |
|
15 ms |
12160 KB |
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
const int maxn = 5e5 + 20;
vector<int> adj[maxn] , tmp;
void dfs(int v , int p = -1)
{
if((int)adj[v].size() == 1)
tmp.pb(v);
for(auto u : adj[v])
if(u != p)
dfs(u , v);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
for(int i = 0; i < n - 1; i++)
{
int a , b;
cin >> a >> b;
a-- , b--;
adj[a].pb(b);
adj[b].pb(a);
}
int root = -1;
for(int i = 0; i < n; i++)
if((int)adj[i].size() != 1)
{
root = i;
dfs(i);
break;
}
int k = tmp.size();
cout << (k + 1) / 2 << endl;
if(k & 1)
cout << root + 1 << " " << tmp.back() + 1 << endl , tmp.pop_back();
for(int i = 0; i < k / 2; i++)
cout << tmp[i] + 1 << " " << tmp[i + k / 2] + 1 << endl;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
14 ms |
12032 KB |
Output is correct |
2 |
Correct |
13 ms |
12160 KB |
Output is correct |
3 |
Correct |
14 ms |
12032 KB |
Output is correct |
4 |
Correct |
13 ms |
12032 KB |
Output is correct |
5 |
Correct |
14 ms |
12032 KB |
Output is correct |
6 |
Correct |
15 ms |
12032 KB |
Output is correct |
7 |
Incorrect |
14 ms |
12160 KB |
Breaking single line is causing network to disconnect. |
8 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
14 ms |
12032 KB |
Output is correct |
2 |
Correct |
13 ms |
12160 KB |
Output is correct |
3 |
Correct |
14 ms |
12032 KB |
Output is correct |
4 |
Correct |
13 ms |
12032 KB |
Output is correct |
5 |
Correct |
14 ms |
12032 KB |
Output is correct |
6 |
Correct |
15 ms |
12032 KB |
Output is correct |
7 |
Incorrect |
14 ms |
12160 KB |
Breaking single line is causing network to disconnect. |
8 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
14 ms |
12032 KB |
Output is correct |
2 |
Correct |
13 ms |
12160 KB |
Output is correct |
3 |
Correct |
14 ms |
12032 KB |
Output is correct |
4 |
Correct |
13 ms |
12032 KB |
Output is correct |
5 |
Correct |
14 ms |
12032 KB |
Output is correct |
6 |
Correct |
15 ms |
12032 KB |
Output is correct |
7 |
Incorrect |
14 ms |
12160 KB |
Breaking single line is causing network to disconnect. |
8 |
Halted |
0 ms |
0 KB |
- |