| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 394636 |
2021-04-27T06:29:08 Z |
negar_a |
Network (BOI15_net) |
C++14 |
|
498 ms |
53200 KB |
//!yrt tsuj uoy srettam gnihton no emoc
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define pb push_back
#define mp make_pair
#define pii pair <int, int>
#define fast_io ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define F first
#define S second
const int maxn = 5e5 + 5;
vector <int> adj[maxn];
int st[maxn];
int tim = 0;
void dfs(int v, int p = -1){
st[v] = tim;
tim ++;
for(int u : adj[v]){
if(u != p){
dfs(u, v);
}
}
}
int main(){
fast_io;
int n;
cin >> n;
for(int i = 0; i < n - 1; i ++){
int x, y;
cin >> x >> y;
x --; y --;
adj[x].pb(y);
adj[y].pb(x);
}
int l = 0;
int r = 0;
for(int i = 0; i < n; i ++){
if((int)adj[i].size() == 1){
l ++;
}else{
r = i;
}
}
dfs(r);
vector <pii> vec;
for(int i = 0; i < n; i ++){
if((int)adj[i].size() == 1){
vec.pb({st[i], i + 1});
}
}
sort(vec.begin(), vec.end());
cout << (l + 1) / 2 << '\n';
for(int i = 0; i < l / 2; i ++){
cout << vec[i].S << " " << vec[i + l / 2].S << '\n';
}
if(l % 2){
cout << vec[l - 1].S << " " << vec[0].S << '\n';
}
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 4 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
8 ms |
12056 KB |
Output is correct |
| 6 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
8 ms |
12064 KB |
Output is correct |
| 11 |
Correct |
8 ms |
11952 KB |
Output is correct |
| 12 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
8 ms |
11988 KB |
Output is correct |
| 14 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 15 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
8 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 |
8 ms |
12056 KB |
Output is correct |
| 20 |
Correct |
10 ms |
11988 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 4 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
8 ms |
12056 KB |
Output is correct |
| 6 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
8 ms |
12064 KB |
Output is correct |
| 11 |
Correct |
8 ms |
11952 KB |
Output is correct |
| 12 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
8 ms |
11988 KB |
Output is correct |
| 14 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 15 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
8 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 |
8 ms |
12056 KB |
Output is correct |
| 20 |
Correct |
10 ms |
11988 KB |
Output is correct |
| 21 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 22 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 23 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 24 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 25 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 26 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 27 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 28 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 29 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 30 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 31 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 32 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 33 |
Correct |
8 ms |
12044 KB |
Output is correct |
| 34 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 35 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 36 |
Correct |
7 ms |
11956 KB |
Output is correct |
| 37 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 38 |
Correct |
7 ms |
12108 KB |
Output is correct |
| 39 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 40 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 41 |
Correct |
8 ms |
12024 KB |
Output is correct |
| 42 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 43 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 44 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 45 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 46 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 47 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 48 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 49 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 50 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 51 |
Correct |
8 ms |
11948 KB |
Output is correct |
| 52 |
Correct |
8 ms |
11992 KB |
Output is correct |
| 53 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 54 |
Correct |
8 ms |
12052 KB |
Output is correct |
| 55 |
Correct |
10 ms |
12048 KB |
Output is correct |
| 56 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 57 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 58 |
Correct |
9 ms |
12184 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 2 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 4 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
8 ms |
12056 KB |
Output is correct |
| 6 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
8 ms |
12064 KB |
Output is correct |
| 11 |
Correct |
8 ms |
11952 KB |
Output is correct |
| 12 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
8 ms |
11988 KB |
Output is correct |
| 14 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 15 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
8 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 |
8 ms |
12056 KB |
Output is correct |
| 20 |
Correct |
10 ms |
11988 KB |
Output is correct |
| 21 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 22 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 23 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 24 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 25 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 26 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 27 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 28 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 29 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 30 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 31 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 32 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 33 |
Correct |
8 ms |
12044 KB |
Output is correct |
| 34 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 35 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 36 |
Correct |
7 ms |
11956 KB |
Output is correct |
| 37 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 38 |
Correct |
7 ms |
12108 KB |
Output is correct |
| 39 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 40 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 41 |
Correct |
8 ms |
12024 KB |
Output is correct |
| 42 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 43 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 44 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 45 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 46 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 47 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 48 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 49 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 50 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 51 |
Correct |
8 ms |
11948 KB |
Output is correct |
| 52 |
Correct |
8 ms |
11992 KB |
Output is correct |
| 53 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 54 |
Correct |
8 ms |
12052 KB |
Output is correct |
| 55 |
Correct |
10 ms |
12048 KB |
Output is correct |
| 56 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 57 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 58 |
Correct |
9 ms |
12184 KB |
Output is correct |
| 59 |
Correct |
408 ms |
32980 KB |
Output is correct |
| 60 |
Correct |
482 ms |
35352 KB |
Output is correct |
| 61 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 62 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 63 |
Correct |
351 ms |
31004 KB |
Output is correct |
| 64 |
Correct |
10 ms |
12364 KB |
Output is correct |
| 65 |
Correct |
18 ms |
13572 KB |
Output is correct |
| 66 |
Correct |
138 ms |
23492 KB |
Output is correct |
| 67 |
Correct |
490 ms |
53200 KB |
Output is correct |
| 68 |
Correct |
498 ms |
46124 KB |
Output is correct |
| 69 |
Correct |
16 ms |
12876 KB |
Output is correct |
| 70 |
Correct |
108 ms |
20496 KB |
Output is correct |
| 71 |
Correct |
370 ms |
39188 KB |
Output is correct |
| 72 |
Correct |
384 ms |
38152 KB |
Output is correct |
| 73 |
Correct |
98 ms |
18244 KB |
Output is correct |
| 74 |
Correct |
470 ms |
33932 KB |
Output is correct |
| 75 |
Correct |
36 ms |
15040 KB |
Output is correct |
| 76 |
Correct |
372 ms |
38620 KB |
Output is correct |
| 77 |
Correct |
362 ms |
38980 KB |
Output is correct |
| 78 |
Correct |
36 ms |
15076 KB |
Output is correct |
| 79 |
Correct |
480 ms |
40308 KB |
Output is correct |
| 80 |
Correct |
10 ms |
12236 KB |
Output is correct |
| 81 |
Correct |
114 ms |
20292 KB |
Output is correct |
| 82 |
Correct |
419 ms |
36552 KB |
Output is correct |
| 83 |
Correct |
465 ms |
33976 KB |
Output is correct |
| 84 |
Correct |
474 ms |
33968 KB |
Output is correct |
| 85 |
Correct |
471 ms |
33928 KB |
Output is correct |
| 86 |
Correct |
471 ms |
35368 KB |
Output is correct |
| 87 |
Correct |
475 ms |
35500 KB |
Output is correct |
