| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 394604 |
2021-04-27T05:46:13 Z |
sinamhdv |
Network (BOI15_net) |
C++11 |
|
524 ms |
58820 KB |
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1000 * 1000 * 1000 + 7;
const int INF = 1e9 + 100;
const ll LINF = 1e18 + 100;
#ifdef DEBUG
#define dbg(x) cout << #x << " = " << (x) << endl << flush;
#define dbgr(s, f) { cout << #s << ": "; for (auto _ = (s); _ != (f); _++) cout << *_ << ' '; cout << endl << flush; }
#else
#define dbg(x) ;
#define dbgr(s, f) ;
#endif
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define fast_io ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define mp make_pair
#define fr first
#define sc second
#define endl '\n'
#define MAXN 500100
int n;
vector<int> adj[MAXN];
vector<pii> ans;
vector<int> leaf;
void dfs(int v, int par)
{
if ((int)adj[v].size() == 1) leaf.pb(v);
for (int u : adj[v])
{
if (u == par) continue;
dfs(u, v);
}
}
int32_t main(void)
{
fast_io;
cin >> n;
FOR(i, 0, n - 1)
{
int x, y;
cin >> x >> y;
adj[x].pb(y);
adj[y].pb(x);
}
int rt = 1;
FOR(i, 1, n + 1) if ((int)adj[i].size() > 1) rt = i;
dfs(rt, -1);
int L = leaf.size();
FOR(i, 0, L/2)
ans.pb({leaf[i], leaf[i + L/2]});
if (L % 2) ans.pb({leaf[L - 2], leaf[L - 1]});
cout << ans.size() << endl;
for (pii p : ans) cout << p.fr << ' ' << p.sc << endl;
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 4 |
Correct |
8 ms |
12064 KB |
Output is correct |
| 5 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
21 ms |
11972 KB |
Output is correct |
| 10 |
Correct |
8 ms |
12060 KB |
Output is correct |
| 11 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
8 ms |
12032 KB |
Output is correct |
| 13 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 14 |
Correct |
7 ms |
12044 KB |
Output is correct |
| 15 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
10 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 18 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 19 |
Correct |
9 ms |
11952 KB |
Output is correct |
| 20 |
Correct |
8 ms |
11980 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 4 |
Correct |
8 ms |
12064 KB |
Output is correct |
| 5 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
21 ms |
11972 KB |
Output is correct |
| 10 |
Correct |
8 ms |
12060 KB |
Output is correct |
| 11 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
8 ms |
12032 KB |
Output is correct |
| 13 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 14 |
Correct |
7 ms |
12044 KB |
Output is correct |
| 15 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
10 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 18 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 19 |
Correct |
9 ms |
11952 KB |
Output is correct |
| 20 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 21 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 22 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 23 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 24 |
Correct |
9 ms |
12164 KB |
Output is correct |
| 25 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 26 |
Correct |
8 ms |
12152 KB |
Output is correct |
| 27 |
Correct |
10 ms |
12108 KB |
Output is correct |
| 28 |
Correct |
10 ms |
12108 KB |
Output is correct |
| 29 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 30 |
Correct |
8 ms |
12064 KB |
Output is correct |
| 31 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 32 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 33 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 34 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 35 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 36 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 37 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 38 |
Correct |
10 ms |
12108 KB |
Output is correct |
| 39 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 40 |
Correct |
12 ms |
11980 KB |
Output is correct |
| 41 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 42 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 43 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 44 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 45 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 46 |
Correct |
10 ms |
11980 KB |
Output is correct |
| 47 |
Correct |
8 ms |
11976 KB |
Output is correct |
| 48 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 49 |
Correct |
9 ms |
12120 KB |
Output is correct |
| 50 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 51 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 52 |
Correct |
8 ms |
11996 KB |
Output is correct |
| 53 |
Correct |
9 ms |
12072 KB |
Output is correct |
| 54 |
Correct |
16 ms |
12016 KB |
Output is correct |
| 55 |
Correct |
8 ms |
12036 KB |
Output is correct |
| 56 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 57 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 58 |
Correct |
9 ms |
12180 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 4 |
Correct |
8 ms |
12064 KB |
Output is correct |
| 5 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
21 ms |
11972 KB |
Output is correct |
| 10 |
Correct |
8 ms |
12060 KB |
Output is correct |
| 11 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
8 ms |
12032 KB |
Output is correct |
| 13 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 14 |
Correct |
7 ms |
12044 KB |
Output is correct |
| 15 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
10 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 18 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 19 |
Correct |
9 ms |
11952 KB |
Output is correct |
| 20 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 21 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 22 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 23 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 24 |
Correct |
9 ms |
12164 KB |
Output is correct |
| 25 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 26 |
Correct |
8 ms |
12152 KB |
Output is correct |
| 27 |
Correct |
10 ms |
12108 KB |
Output is correct |
| 28 |
Correct |
10 ms |
12108 KB |
Output is correct |
| 29 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 30 |
Correct |
8 ms |
12064 KB |
Output is correct |
| 31 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 32 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 33 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 34 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 35 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 36 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 37 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 38 |
Correct |
10 ms |
12108 KB |
Output is correct |
| 39 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 40 |
Correct |
12 ms |
11980 KB |
Output is correct |
| 41 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 42 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 43 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 44 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 45 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 46 |
Correct |
10 ms |
11980 KB |
Output is correct |
| 47 |
Correct |
8 ms |
11976 KB |
Output is correct |
| 48 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 49 |
Correct |
9 ms |
12120 KB |
Output is correct |
| 50 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 51 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 52 |
Correct |
8 ms |
11996 KB |
Output is correct |
| 53 |
Correct |
9 ms |
12072 KB |
Output is correct |
| 54 |
Correct |
16 ms |
12016 KB |
Output is correct |
| 55 |
Correct |
8 ms |
12036 KB |
Output is correct |
| 56 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 57 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 58 |
Correct |
9 ms |
12180 KB |
Output is correct |
| 59 |
Correct |
389 ms |
31168 KB |
Output is correct |
| 60 |
Correct |
488 ms |
33392 KB |
Output is correct |
| 61 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 62 |
Correct |
11 ms |
11980 KB |
Output is correct |
| 63 |
Correct |
329 ms |
29400 KB |
Output is correct |
| 64 |
Correct |
9 ms |
12364 KB |
Output is correct |
| 65 |
Correct |
19 ms |
13700 KB |
Output is correct |
| 66 |
Correct |
167 ms |
24540 KB |
Output is correct |
| 67 |
Correct |
517 ms |
58820 KB |
Output is correct |
| 68 |
Correct |
524 ms |
49416 KB |
Output is correct |
| 69 |
Correct |
15 ms |
12748 KB |
Output is correct |
| 70 |
Correct |
90 ms |
19760 KB |
Output is correct |
| 71 |
Correct |
343 ms |
37032 KB |
Output is correct |
| 72 |
Correct |
395 ms |
36104 KB |
Output is correct |
| 73 |
Correct |
96 ms |
17608 KB |
Output is correct |
| 74 |
Correct |
451 ms |
32004 KB |
Output is correct |
| 75 |
Correct |
32 ms |
14784 KB |
Output is correct |
| 76 |
Correct |
328 ms |
36636 KB |
Output is correct |
| 77 |
Correct |
338 ms |
37180 KB |
Output is correct |
| 78 |
Correct |
32 ms |
15104 KB |
Output is correct |
| 79 |
Correct |
489 ms |
42020 KB |
Output is correct |
| 80 |
Correct |
9 ms |
12236 KB |
Output is correct |
| 81 |
Correct |
104 ms |
19724 KB |
Output is correct |
| 82 |
Correct |
378 ms |
34560 KB |
Output is correct |
| 83 |
Correct |
423 ms |
32056 KB |
Output is correct |
| 84 |
Correct |
427 ms |
31992 KB |
Output is correct |
| 85 |
Correct |
416 ms |
31956 KB |
Output is correct |
| 86 |
Correct |
425 ms |
33468 KB |
Output is correct |
| 87 |
Correct |
417 ms |
33460 KB |
Output is correct |
