| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 436724 |
2021-06-24T19:48:19 Z |
ak2006 |
Network (BOI15_net) |
C++14 |
|
706 ms |
51576 KB |
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vb = vector<bool>;
using vvb = vector<vb>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vc = vector<char>;
using vvc = vector<vc>;
using vs = vector<string>;
const ll mod = 1e9 + 7,inf = 1e18;
#define pb push_back
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
void setIO()
{
fast;
}
int n = 5e5 + 5,t;
vvi adj(n);
vi in(n),out(n),leaves;
void dfs(int u,int p)
{
in[u] = ++t;
for (int v:adj[u])if (v != p)
dfs(v,u);
out[u] = ++t;
if (adj[u].size() == 1)leaves.pb(u);//leaves includes the root
}
bool cmp(int a,int b)
{
return in[a] < in[b];
}
int main()
{
setIO();
cin>>n;
for (int i = 0;i<n - 1;i++){int u,v;cin>>u>>v;adj[u].pb(v),adj[v].pb(u);}
dfs(1,-1);
sort(leaves.begin(),leaves.end(),cmp);
int ans = (int)leaves.size();
ans = (ans%2 == 1 ? ans/2 + 1 : ans/2);
cout<<ans<<'\n';
for (int i = 0;i<(int)leaves.size()/2;i++)
cout<<leaves[i]<<" "<<leaves[(i + ans)%(int)leaves.size()]<<'\n';
if ((int)leaves.size()%2 == 1)
cout<<leaves[(int)leaves.size()/2]<<" "<<leaves[0];
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 2 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 3 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 4 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 5 |
Correct |
12 ms |
15904 KB |
Output is correct |
| 6 |
Correct |
13 ms |
15976 KB |
Output is correct |
| 7 |
Correct |
12 ms |
15988 KB |
Output is correct |
| 8 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 9 |
Correct |
11 ms |
15984 KB |
Output is correct |
| 10 |
Correct |
12 ms |
15912 KB |
Output is correct |
| 11 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 12 |
Correct |
14 ms |
15948 KB |
Output is correct |
| 13 |
Correct |
11 ms |
15944 KB |
Output is correct |
| 14 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 15 |
Correct |
12 ms |
15936 KB |
Output is correct |
| 16 |
Correct |
11 ms |
15984 KB |
Output is correct |
| 17 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 18 |
Correct |
12 ms |
15992 KB |
Output is correct |
| 19 |
Correct |
12 ms |
15892 KB |
Output is correct |
| 20 |
Correct |
11 ms |
15948 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 2 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 3 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 4 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 5 |
Correct |
12 ms |
15904 KB |
Output is correct |
| 6 |
Correct |
13 ms |
15976 KB |
Output is correct |
| 7 |
Correct |
12 ms |
15988 KB |
Output is correct |
| 8 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 9 |
Correct |
11 ms |
15984 KB |
Output is correct |
| 10 |
Correct |
12 ms |
15912 KB |
Output is correct |
| 11 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 12 |
Correct |
14 ms |
15948 KB |
Output is correct |
| 13 |
Correct |
11 ms |
15944 KB |
Output is correct |
| 14 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 15 |
Correct |
12 ms |
15936 KB |
Output is correct |
| 16 |
Correct |
11 ms |
15984 KB |
Output is correct |
| 17 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 18 |
Correct |
12 ms |
15992 KB |
Output is correct |
| 19 |
Correct |
12 ms |
15892 KB |
Output is correct |
| 20 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 21 |
Correct |
12 ms |
15972 KB |
Output is correct |
| 22 |
Correct |
13 ms |
16076 KB |
Output is correct |
| 23 |
Correct |
13 ms |
15996 KB |
Output is correct |
| 24 |
Correct |
12 ms |
16076 KB |
Output is correct |
| 25 |
Correct |
12 ms |
16076 KB |
Output is correct |
| 26 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 27 |
Correct |
12 ms |
15996 KB |
Output is correct |
| 28 |
Correct |
13 ms |
15980 KB |
Output is correct |
| 29 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 30 |
Correct |
11 ms |
15888 KB |
Output is correct |
| 31 |
Correct |
13 ms |
15996 KB |
Output is correct |
| 32 |
Correct |
11 ms |
15872 KB |
Output is correct |
| 33 |
Correct |
11 ms |
15872 KB |
Output is correct |
| 34 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 35 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 36 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 37 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 38 |
Correct |
12 ms |
16036 KB |
Output is correct |
| 39 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 40 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 41 |
Correct |
12 ms |
15892 KB |
Output is correct |
| 42 |
Correct |
11 ms |
15908 KB |
Output is correct |
| 43 |
Correct |
11 ms |
16044 KB |
Output is correct |
| 44 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 45 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 46 |
Correct |
11 ms |
15984 KB |
Output is correct |
| 47 |
Correct |
11 ms |
15980 KB |
Output is correct |
| 48 |
Correct |
12 ms |
15992 KB |
Output is correct |
| 49 |
Correct |
11 ms |
15972 KB |
Output is correct |
| 50 |
Correct |
12 ms |
15912 KB |
Output is correct |
| 51 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 52 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 53 |
Correct |
12 ms |
16040 KB |
Output is correct |
| 54 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 55 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 56 |
Correct |
12 ms |
15892 KB |
Output is correct |
| 57 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 58 |
Correct |
13 ms |
16076 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 2 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 3 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 4 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 5 |
Correct |
12 ms |
15904 KB |
Output is correct |
| 6 |
Correct |
13 ms |
15976 KB |
Output is correct |
| 7 |
Correct |
12 ms |
15988 KB |
Output is correct |
| 8 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 9 |
Correct |
11 ms |
15984 KB |
Output is correct |
| 10 |
Correct |
12 ms |
15912 KB |
Output is correct |
| 11 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 12 |
Correct |
14 ms |
15948 KB |
Output is correct |
| 13 |
Correct |
11 ms |
15944 KB |
Output is correct |
| 14 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 15 |
Correct |
12 ms |
15936 KB |
Output is correct |
| 16 |
Correct |
11 ms |
15984 KB |
Output is correct |
| 17 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 18 |
Correct |
12 ms |
15992 KB |
Output is correct |
| 19 |
Correct |
12 ms |
15892 KB |
Output is correct |
| 20 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 21 |
Correct |
12 ms |
15972 KB |
Output is correct |
| 22 |
Correct |
13 ms |
16076 KB |
Output is correct |
| 23 |
Correct |
13 ms |
15996 KB |
Output is correct |
| 24 |
Correct |
12 ms |
16076 KB |
Output is correct |
| 25 |
Correct |
12 ms |
16076 KB |
Output is correct |
| 26 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 27 |
Correct |
12 ms |
15996 KB |
Output is correct |
| 28 |
Correct |
13 ms |
15980 KB |
Output is correct |
| 29 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 30 |
Correct |
11 ms |
15888 KB |
Output is correct |
| 31 |
Correct |
13 ms |
15996 KB |
Output is correct |
| 32 |
Correct |
11 ms |
15872 KB |
Output is correct |
| 33 |
Correct |
11 ms |
15872 KB |
Output is correct |
| 34 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 35 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 36 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 37 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 38 |
Correct |
12 ms |
16036 KB |
Output is correct |
| 39 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 40 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 41 |
Correct |
12 ms |
15892 KB |
Output is correct |
| 42 |
Correct |
11 ms |
15908 KB |
Output is correct |
| 43 |
Correct |
11 ms |
16044 KB |
Output is correct |
| 44 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 45 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 46 |
Correct |
11 ms |
15984 KB |
Output is correct |
| 47 |
Correct |
11 ms |
15980 KB |
Output is correct |
| 48 |
Correct |
12 ms |
15992 KB |
Output is correct |
| 49 |
Correct |
11 ms |
15972 KB |
Output is correct |
| 50 |
Correct |
12 ms |
15912 KB |
Output is correct |
| 51 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 52 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 53 |
Correct |
12 ms |
16040 KB |
Output is correct |
| 54 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 55 |
Correct |
12 ms |
15948 KB |
Output is correct |
| 56 |
Correct |
12 ms |
15892 KB |
Output is correct |
| 57 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 58 |
Correct |
13 ms |
16076 KB |
Output is correct |
| 59 |
Correct |
591 ms |
39980 KB |
Output is correct |
| 60 |
Correct |
671 ms |
42660 KB |
Output is correct |
| 61 |
Correct |
11 ms |
15948 KB |
Output is correct |
| 62 |
Correct |
12 ms |
15900 KB |
Output is correct |
| 63 |
Correct |
523 ms |
37420 KB |
Output is correct |
| 64 |
Correct |
14 ms |
16332 KB |
Output is correct |
| 65 |
Correct |
23 ms |
17728 KB |
Output is correct |
| 66 |
Correct |
170 ms |
31752 KB |
Output is correct |
| 67 |
Correct |
615 ms |
50940 KB |
Output is correct |
| 68 |
Correct |
587 ms |
51576 KB |
Output is correct |
| 69 |
Correct |
20 ms |
16844 KB |
Output is correct |
| 70 |
Correct |
155 ms |
25068 KB |
Output is correct |
| 71 |
Correct |
569 ms |
45748 KB |
Output is correct |
| 72 |
Correct |
596 ms |
44508 KB |
Output is correct |
| 73 |
Correct |
128 ms |
22976 KB |
Output is correct |
| 74 |
Correct |
641 ms |
41520 KB |
Output is correct |
| 75 |
Correct |
47 ms |
19140 KB |
Output is correct |
| 76 |
Correct |
581 ms |
45440 KB |
Output is correct |
| 77 |
Correct |
598 ms |
45520 KB |
Output is correct |
| 78 |
Correct |
40 ms |
19268 KB |
Output is correct |
| 79 |
Correct |
619 ms |
49156 KB |
Output is correct |
| 80 |
Correct |
13 ms |
16280 KB |
Output is correct |
| 81 |
Correct |
197 ms |
25180 KB |
Output is correct |
| 82 |
Correct |
547 ms |
43452 KB |
Output is correct |
| 83 |
Correct |
663 ms |
41528 KB |
Output is correct |
| 84 |
Correct |
654 ms |
41556 KB |
Output is correct |
| 85 |
Correct |
600 ms |
41644 KB |
Output is correct |
| 86 |
Correct |
698 ms |
42680 KB |
Output is correct |
| 87 |
Correct |
706 ms |
42720 KB |
Output is correct |
