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Submission #580238

# Submission time Handle Problem Language Result Execution time Memory
580238 2022-06-20T19:14:38 Z Omar_Elgedawy Network (BOI15_net) C++14
18 / 100
 16 ms 23936 KB 
#include <bits/stdc++.h>
using namespace std;
#define cin(vec)        for(auto& i : vec) cin >> i
#define cout(vec)       for(auto& i : vec) cout << i << " "; cout << "\n";
#define fast            ios::sync_with_stdio(0);cin.tie(0);
#define loop(i,a,b)     for (int i = a; i < b; i++)
#define F               first
#define S               second
#define pb(n)           push_back(n)
#define pf(n)           push_front(n)
#define dci(d)          fixed<<setprecision(d)
#define sp              ' '
#define el              '\n'
#define all(v)          v.begin(),v.end()
#define int             long long
int dx[8]= {0,0,1,-1,-1,1,1,-1};
int dy[8]= {-1,1,0,0,-1,1,-1,1};
int const N=5e5+5,M=1e3+1,Mod=1e9+7;
vector<int>adj[N],par[N];
int n,dep[N];
void testcase(int h){
  cin>>n;
  for(int i=0;i<n-1;i++){
    int u,v;cin>>u>>v;
    adj[u].pb(v);
    adj[v].pb(u);
    dep[u]++;
    dep[v]++;
  }
  deque<pair<int,int>>ans;
  vector<pair<int,int>>leaf;
  for(int i=1;i<=n;i++){
    if(dep[i]==1){
      leaf.push_back({adj[i][0],i});
    }
  }
  sort(all(leaf));
  int sz=leaf.size();
  if(sz%2){
    cout<<sz/2+1<<el;
    for(int i=0;i<sz/2;i++){
      cout<<leaf[i].S<<' '<<leaf[i+sz/2+1].S<<el;
    }
    cout<<leaf[sz/2].S<<' '<<1<<el;
  }
  else{
    cout<<sz/2<<el;
    for(int i=0;i<sz/2;i++){
      cout<<leaf[i].S<<' '<<leaf[i+sz/2].S<<el;
    }
  }
}
int32_t main()
{
  // fast
  testcase(1);
  // int tc;cin>>tc;for(int i=1;i<=tc;i++)testcase(i);
  return 0;
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23764 KB Output is correct
2 Correct 13 ms 23700 KB Output is correct
3 Correct 12 ms 23724 KB Output is correct
4 Correct 13 ms 23752 KB Output is correct
5 Correct 13 ms 23764 KB Output is correct
6 Correct 12 ms 23708 KB Output is correct
7 Correct 12 ms 23800 KB Output is correct
8 Correct 12 ms 23892 KB Output is correct
9 Correct 15 ms 23764 KB Output is correct
10 Correct 16 ms 23776 KB Output is correct
11 Correct 13 ms 23792 KB Output is correct
12 Correct 14 ms 23744 KB Output is correct
13 Correct 13 ms 23780 KB Output is correct
14 Correct 13 ms 23764 KB Output is correct
15 Correct 12 ms 23764 KB Output is correct
16 Correct 12 ms 23792 KB Output is correct
17 Correct 12 ms 23712 KB Output is correct
18 Correct 12 ms 23792 KB Output is correct
19 Correct 12 ms 23764 KB Output is correct
20 Correct 14 ms 23764 KB Output is correct

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23764 KB Output is correct
2 Correct 13 ms 23700 KB Output is correct
3 Correct 12 ms 23724 KB Output is correct
4 Correct 13 ms 23752 KB Output is correct
5 Correct 13 ms 23764 KB Output is correct
6 Correct 12 ms 23708 KB Output is correct
7 Correct 12 ms 23800 KB Output is correct
8 Correct 12 ms 23892 KB Output is correct
9 Correct 15 ms 23764 KB Output is correct
10 Correct 16 ms 23776 KB Output is correct
11 Correct 13 ms 23792 KB Output is correct
12 Correct 14 ms 23744 KB Output is correct
13 Correct 13 ms 23780 KB Output is correct
14 Correct 13 ms 23764 KB Output is correct
15 Correct 12 ms 23764 KB Output is correct
16 Correct 12 ms 23792 KB Output is correct
17 Correct 12 ms 23712 KB Output is correct
18 Correct 12 ms 23792 KB Output is correct
19 Correct 12 ms 23764 KB Output is correct
20 Correct 14 ms 23764 KB Output is correct
21 Correct 12 ms 23764 KB Output is correct
22 Correct 15 ms 23928 KB Output is correct
23 Correct 15 ms 23936 KB Output is correct
24 Correct 14 ms 23892 KB Output is correct
25 Correct 14 ms 23892 KB Output is correct
26 Correct 15 ms 23892 KB Output is correct
27 Correct 13 ms 23844 KB Output is correct
28 Correct 14 ms 23892 KB Output is correct
29 Correct 12 ms 23892 KB Output is correct
30 Correct 12 ms 23764 KB Output is correct
31 Correct 14 ms 23892 KB Output is correct
32 Correct 13 ms 23712 KB Output is correct
33 Correct 13 ms 23772 KB Output is correct
34 Incorrect 12 ms 23764 KB Breaking single line is causing network to disconnect.
35 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 23764 KB Output is correct
2 Correct 13 ms 23700 KB Output is correct
3 Correct 12 ms 23724 KB Output is correct
4 Correct 13 ms 23752 KB Output is correct
5 Correct 13 ms 23764 KB Output is correct
6 Correct 12 ms 23708 KB Output is correct
7 Correct 12 ms 23800 KB Output is correct
8 Correct 12 ms 23892 KB Output is correct
9 Correct 15 ms 23764 KB Output is correct
10 Correct 16 ms 23776 KB Output is correct
11 Correct 13 ms 23792 KB Output is correct
12 Correct 14 ms 23744 KB Output is correct
13 Correct 13 ms 23780 KB Output is correct
14 Correct 13 ms 23764 KB Output is correct
15 Correct 12 ms 23764 KB Output is correct
16 Correct 12 ms 23792 KB Output is correct
17 Correct 12 ms 23712 KB Output is correct
18 Correct 12 ms 23792 KB Output is correct
19 Correct 12 ms 23764 KB Output is correct
20 Correct 14 ms 23764 KB Output is correct
21 Correct 12 ms 23764 KB Output is correct
22 Correct 15 ms 23928 KB Output is correct
23 Correct 15 ms 23936 KB Output is correct
24 Correct 14 ms 23892 KB Output is correct
25 Correct 14 ms 23892 KB Output is correct
26 Correct 15 ms 23892 KB Output is correct
27 Correct 13 ms 23844 KB Output is correct
28 Correct 14 ms 23892 KB Output is correct
29 Correct 12 ms 23892 KB Output is correct
30 Correct 12 ms 23764 KB Output is correct
31 Correct 14 ms 23892 KB Output is correct
32 Correct 13 ms 23712 KB Output is correct
33 Correct 13 ms 23772 KB Output is correct
34 Incorrect 12 ms 23764 KB Breaking single line is causing network to disconnect.
35 Halted 0 ms 0 KB -