| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 395013 |
2021-04-27T15:35:48 Z |
soroush |
Network (BOI15_net) |
C++17 |
|
491 ms |
63428 KB |
//曇り空 のぞいた予感
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int , int> pii;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 5e5 + 100;
const ll mod = 1e9+7;
#define pb push_back
#define endl '\n'
#define dokme(x) cout << x , exit(0)
#define ms(x , y) memset(x , y , sizeof x)
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}
#define sz(x) int(x.size())
int n;
vector < int > adj[maxn] , leaf;
void dfs(int v , int par = 0){
for(auto u : adj[v])if(u ^ par)
dfs(u , v);
if(sz(adj[v]) == 1)leaf.pb(v);
}
int32_t main(){
ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
cin >> n;
int root;
for(int i = 1 ; i < n ; i ++){
int u , v;
cin >> u >> v;
adj[u].pb(v);
adj[v].pb(u);
}
for(int i = 1 ; i <= n ; i ++)
if(sz(adj[i]) > 1)root = i;
dfs(root);
cout << (sz(leaf)+1)/2 << endl;
for(int i = 0 ; i < (sz(leaf)+1)/2 ; i ++)
cout << leaf[i] << ' ' << leaf[i + sz(leaf)/2] << endl;
return(0);
}
Compilation message
net.cpp: In function 'int32_t main()':
net.cpp:44:5: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
44 | dfs(root);
| ~~~^~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 4 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 8 |
Correct |
7 ms |
12020 KB |
Output is correct |
| 9 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 11 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 14 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 15 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
7 ms |
12036 KB |
Output is correct |
| 18 |
Correct |
7 ms |
12032 KB |
Output is correct |
| 19 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 20 |
Correct |
7 ms |
12020 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 4 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 8 |
Correct |
7 ms |
12020 KB |
Output is correct |
| 9 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 11 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 14 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 15 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
7 ms |
12036 KB |
Output is correct |
| 18 |
Correct |
7 ms |
12032 KB |
Output is correct |
| 19 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 20 |
Correct |
7 ms |
12020 KB |
Output is correct |
| 21 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 22 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 23 |
Correct |
8 ms |
12076 KB |
Output is correct |
| 24 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 25 |
Correct |
8 ms |
12084 KB |
Output is correct |
| 26 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 27 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 28 |
Correct |
8 ms |
12052 KB |
Output is correct |
| 29 |
Correct |
8 ms |
12092 KB |
Output is correct |
| 30 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 31 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 32 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 33 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 34 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 35 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 36 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 37 |
Correct |
7 ms |
12092 KB |
Output is correct |
| 38 |
Correct |
7 ms |
12108 KB |
Output is correct |
| 39 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 40 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 41 |
Correct |
7 ms |
11984 KB |
Output is correct |
| 42 |
Correct |
7 ms |
12076 KB |
Output is correct |
| 43 |
Correct |
7 ms |
12108 KB |
Output is correct |
| 44 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 45 |
Correct |
7 ms |
11972 KB |
Output is correct |
| 46 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 47 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 48 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 49 |
Correct |
8 ms |
12008 KB |
Output is correct |
| 50 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 51 |
Correct |
7 ms |
11988 KB |
Output is correct |
| 52 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 53 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 54 |
Correct |
7 ms |
12076 KB |
Output is correct |
| 55 |
Correct |
7 ms |
12012 KB |
Output is correct |
| 56 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 57 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 58 |
Correct |
8 ms |
12108 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 4 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 8 |
Correct |
7 ms |
12020 KB |
Output is correct |
| 9 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 11 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 14 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 15 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
7 ms |
12036 KB |
Output is correct |
| 18 |
Correct |
7 ms |
12032 KB |
Output is correct |
| 19 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 20 |
Correct |
7 ms |
12020 KB |
Output is correct |
| 21 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 22 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 23 |
Correct |
8 ms |
12076 KB |
Output is correct |
| 24 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 25 |
Correct |
8 ms |
12084 KB |
Output is correct |
| 26 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 27 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 28 |
Correct |
8 ms |
12052 KB |
Output is correct |
| 29 |
Correct |
8 ms |
12092 KB |
Output is correct |
| 30 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 31 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 32 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 33 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 34 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 35 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 36 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 37 |
Correct |
7 ms |
12092 KB |
Output is correct |
| 38 |
Correct |
7 ms |
12108 KB |
Output is correct |
| 39 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 40 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 41 |
Correct |
7 ms |
11984 KB |
Output is correct |
| 42 |
Correct |
7 ms |
12076 KB |
Output is correct |
| 43 |
Correct |
7 ms |
12108 KB |
Output is correct |
| 44 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 45 |
Correct |
7 ms |
11972 KB |
Output is correct |
| 46 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 47 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 48 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 49 |
Correct |
8 ms |
12008 KB |
Output is correct |
| 50 |
Correct |
7 ms |
12068 KB |
Output is correct |
| 51 |
Correct |
7 ms |
11988 KB |
Output is correct |
| 52 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 53 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 54 |
Correct |
7 ms |
12076 KB |
Output is correct |
| 55 |
Correct |
7 ms |
12012 KB |
Output is correct |
| 56 |
Correct |
7 ms |
12064 KB |
Output is correct |
| 57 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 58 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 59 |
Correct |
355 ms |
34300 KB |
Output is correct |
| 60 |
Correct |
429 ms |
36536 KB |
Output is correct |
| 61 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 62 |
Correct |
7 ms |
11948 KB |
Output is correct |
| 63 |
Correct |
304 ms |
32516 KB |
Output is correct |
| 64 |
Correct |
9 ms |
12364 KB |
Output is correct |
| 65 |
Correct |
18 ms |
13900 KB |
Output is correct |
| 66 |
Correct |
129 ms |
26780 KB |
Output is correct |
| 67 |
Correct |
482 ms |
63428 KB |
Output is correct |
| 68 |
Correct |
466 ms |
53740 KB |
Output is correct |
| 69 |
Correct |
13 ms |
12876 KB |
Output is correct |
| 70 |
Correct |
105 ms |
21164 KB |
Output is correct |
| 71 |
Correct |
308 ms |
39324 KB |
Output is correct |
| 72 |
Correct |
324 ms |
38748 KB |
Output is correct |
| 73 |
Correct |
91 ms |
19180 KB |
Output is correct |
| 74 |
Correct |
431 ms |
35260 KB |
Output is correct |
| 75 |
Correct |
31 ms |
15172 KB |
Output is correct |
| 76 |
Correct |
316 ms |
39076 KB |
Output is correct |
| 77 |
Correct |
314 ms |
39324 KB |
Output is correct |
| 78 |
Correct |
33 ms |
15580 KB |
Output is correct |
| 79 |
Correct |
488 ms |
46276 KB |
Output is correct |
| 80 |
Correct |
14 ms |
12236 KB |
Output is correct |
| 81 |
Correct |
137 ms |
21208 KB |
Output is correct |
| 82 |
Correct |
402 ms |
37356 KB |
Output is correct |
| 83 |
Correct |
454 ms |
35412 KB |
Output is correct |
| 84 |
Correct |
474 ms |
35300 KB |
Output is correct |
| 85 |
Correct |
484 ms |
35404 KB |
Output is correct |
| 86 |
Correct |
491 ms |
36472 KB |
Output is correct |
| 87 |
Correct |
476 ms |
36468 KB |
Output is correct |
