/* Man BINAHAYATO Mikham */
#include <bits/stdc++.h>
#define pb push_back
#define endl "\n"
#define ll long long
using namespace std;
const int maxn = 1e6 + 10, Maxn = 1e5 + 10, SQ = 360 , lg = 22 ;
const int mod = 1e9 + 7;
const long long inf = 1e18 + 10;
int sum[maxn], maxx[maxn], cnt, root;
vector<int> adj[maxn], vec;
void find_root(int v, int par){
for(auto u: adj[v]){
if(u == par)
continue;
find_root(u, v);
sum[v] += sum[u];
maxx[v] = max(maxx[v], sum[u]);
}
maxx[v] = max(maxx[v], cnt - sum[v]);
if(maxx[v] <= cnt/2)
root = v;
}
void dfs(int v, int par){
if(adj[v].size() == 1)
vec.pb(v);
for(auto u : adj[v])
if(par != u)
dfs(u, v);
}
int32_t main(){
ios:: sync_with_stdio(0), cin.tie(0), cout.tie(0);
int n;
cin >> n;
for(int i = 0 ; i < n - 1 ; i++){
int u, v;
cin >> u >> v;
u--, v--;
adj[u].pb(v);
adj[v].pb(u);
}
for(int i = 0 ; i < n ; i++)
if(adj[i].size() == 1)
cnt++;
find_root(0, -1);
dfs(root, -1);
int x = cnt/2;
cout << (cnt + 1)/2 << endl;
for(int i = 0 ; i < (cnt + 1)/2 ; i++){
cout << vec[i] + 1 << ' ' << vec[min(cnt - 1, i + x)] + 1 << endl;
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
23756 KB |
Output is correct |
2 |
Correct |
17 ms |
23808 KB |
Output is correct |
3 |
Correct |
15 ms |
23756 KB |
Output is correct |
4 |
Correct |
15 ms |
23696 KB |
Output is correct |
5 |
Correct |
15 ms |
23812 KB |
Output is correct |
6 |
Correct |
15 ms |
23760 KB |
Output is correct |
7 |
Correct |
16 ms |
23808 KB |
Output is correct |
8 |
Correct |
16 ms |
23784 KB |
Output is correct |
9 |
Correct |
15 ms |
23736 KB |
Output is correct |
10 |
Correct |
15 ms |
23804 KB |
Output is correct |
11 |
Correct |
17 ms |
23808 KB |
Output is correct |
12 |
Correct |
18 ms |
23756 KB |
Output is correct |
13 |
Correct |
17 ms |
23756 KB |
Output is correct |
14 |
Correct |
15 ms |
23712 KB |
Output is correct |
15 |
Correct |
16 ms |
23732 KB |
Output is correct |
16 |
Correct |
16 ms |
23692 KB |
Output is correct |
17 |
Correct |
15 ms |
23692 KB |
Output is correct |
18 |
Correct |
16 ms |
23812 KB |
Output is correct |
19 |
Correct |
15 ms |
23756 KB |
Output is correct |
20 |
Correct |
16 ms |
23760 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
23756 KB |
Output is correct |
2 |
Correct |
17 ms |
23808 KB |
Output is correct |
3 |
Correct |
15 ms |
23756 KB |
Output is correct |
4 |
Correct |
15 ms |
23696 KB |
Output is correct |
5 |
Correct |
15 ms |
23812 KB |
Output is correct |
6 |
Correct |
15 ms |
23760 KB |
Output is correct |
7 |
Correct |
16 ms |
23808 KB |
Output is correct |
8 |
Correct |
16 ms |
23784 KB |
Output is correct |
9 |
Correct |
15 ms |
23736 KB |
Output is correct |
10 |
Correct |
15 ms |
23804 KB |
Output is correct |
11 |
Correct |
17 ms |
23808 KB |
Output is correct |
12 |
Correct |
18 ms |
23756 KB |
Output is correct |
13 |
Correct |
17 ms |
23756 KB |
Output is correct |
14 |
Correct |
15 ms |
23712 KB |
Output is correct |
15 |
Correct |
16 ms |
23732 KB |
Output is correct |
16 |
Correct |
16 ms |
23692 KB |
Output is correct |
17 |
Correct |
15 ms |
23692 KB |
Output is correct |
18 |
Correct |
16 ms |
23812 KB |
Output is correct |
19 |
Correct |
15 ms |
23756 KB |
Output is correct |
20 |
Correct |
16 ms |
23760 KB |
Output is correct |
21 |
Correct |
15 ms |
23756 KB |
Output is correct |
22 |
Correct |
16 ms |
24012 KB |
Output is correct |
23 |
Correct |
17 ms |
23920 KB |
Output is correct |
24 |
Correct |
19 ms |
23884 KB |
Output is correct |
25 |
Correct |
16 ms |
23856 KB |
Output is correct |
26 |
Correct |
17 ms |
23888 KB |
Output is correct |
27 |
Correct |
18 ms |
23884 KB |
Output is correct |
28 |
Correct |
16 ms |
23920 KB |
Output is correct |
29 |
Correct |
16 ms |
23884 KB |
Output is correct |
30 |
Correct |
15 ms |
23756 KB |
Output is correct |
31 |
Correct |
16 ms |
23816 KB |
Output is correct |
32 |
Correct |
16 ms |
23776 KB |
Output is correct |
33 |
Correct |
16 ms |
23684 KB |
Output is correct |
34 |
Correct |
16 ms |
23756 KB |
Output is correct |
35 |
Correct |
16 ms |
23756 KB |
Output is correct |
36 |
Correct |
18 ms |
23800 KB |
Output is correct |
37 |
Correct |
16 ms |
23756 KB |
Output is correct |
38 |
Correct |
16 ms |
23884 KB |
Output is correct |
39 |
Correct |
15 ms |
23800 KB |
Output is correct |
40 |
Correct |
15 ms |
23696 KB |
Output is correct |
41 |
Correct |
15 ms |
23756 KB |
Output is correct |
42 |
Correct |
16 ms |
23836 KB |
Output is correct |
43 |
Correct |
16 ms |
23792 KB |
Output is correct |
44 |
Correct |
15 ms |
23808 KB |
Output is correct |
45 |
Correct |
15 ms |
23756 KB |
Output is correct |
46 |
Correct |
16 ms |
23888 KB |
Output is correct |
47 |
Correct |
15 ms |
23688 KB |
Output is correct |
48 |
Correct |
15 ms |
23832 KB |
Output is correct |
49 |
Correct |
16 ms |
23760 KB |
Output is correct |
50 |
Correct |
15 ms |
23700 KB |
Output is correct |
51 |
Correct |
17 ms |
23756 KB |
Output is correct |
52 |
Correct |
14 ms |
23756 KB |
Output is correct |
53 |
Correct |
16 ms |
23812 KB |
Output is correct |
54 |
Correct |
15 ms |
23732 KB |
Output is correct |
55 |
Correct |
16 ms |
23748 KB |
Output is correct |
56 |
Correct |
16 ms |
23804 KB |
Output is correct |
57 |
Correct |
15 ms |
23740 KB |
Output is correct |
58 |
Correct |
16 ms |
23940 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
23756 KB |
Output is correct |
2 |
Correct |
17 ms |
23808 KB |
Output is correct |
3 |
Correct |
15 ms |
23756 KB |
Output is correct |
4 |
Correct |
15 ms |
23696 KB |
Output is correct |
5 |
Correct |
15 ms |
23812 KB |
Output is correct |
6 |
Correct |
15 ms |
23760 KB |
Output is correct |
7 |
Correct |
16 ms |
23808 KB |
Output is correct |
8 |
Correct |
16 ms |
23784 KB |
Output is correct |
9 |
Correct |
15 ms |
23736 KB |
Output is correct |
10 |
Correct |
15 ms |
23804 KB |
Output is correct |
11 |
Correct |
17 ms |
23808 KB |
Output is correct |
12 |
Correct |
18 ms |
23756 KB |
Output is correct |
13 |
Correct |
17 ms |
23756 KB |
Output is correct |
14 |
Correct |
15 ms |
23712 KB |
Output is correct |
15 |
Correct |
16 ms |
23732 KB |
Output is correct |
16 |
Correct |
16 ms |
23692 KB |
Output is correct |
17 |
Correct |
15 ms |
23692 KB |
Output is correct |
18 |
Correct |
16 ms |
23812 KB |
Output is correct |
19 |
Correct |
15 ms |
23756 KB |
Output is correct |
20 |
Correct |
16 ms |
23760 KB |
Output is correct |
21 |
Correct |
15 ms |
23756 KB |
Output is correct |
22 |
Correct |
16 ms |
24012 KB |
Output is correct |
23 |
Correct |
17 ms |
23920 KB |
Output is correct |
24 |
Correct |
19 ms |
23884 KB |
Output is correct |
25 |
Correct |
16 ms |
23856 KB |
Output is correct |
26 |
Correct |
17 ms |
23888 KB |
Output is correct |
27 |
Correct |
18 ms |
23884 KB |
Output is correct |
28 |
Correct |
16 ms |
23920 KB |
Output is correct |
29 |
Correct |
16 ms |
23884 KB |
Output is correct |
30 |
Correct |
15 ms |
23756 KB |
Output is correct |
31 |
Correct |
16 ms |
23816 KB |
Output is correct |
32 |
Correct |
16 ms |
23776 KB |
Output is correct |
33 |
Correct |
16 ms |
23684 KB |
Output is correct |
34 |
Correct |
16 ms |
23756 KB |
Output is correct |
35 |
Correct |
16 ms |
23756 KB |
Output is correct |
36 |
Correct |
18 ms |
23800 KB |
Output is correct |
37 |
Correct |
16 ms |
23756 KB |
Output is correct |
38 |
Correct |
16 ms |
23884 KB |
Output is correct |
39 |
Correct |
15 ms |
23800 KB |
Output is correct |
40 |
Correct |
15 ms |
23696 KB |
Output is correct |
41 |
Correct |
15 ms |
23756 KB |
Output is correct |
42 |
Correct |
16 ms |
23836 KB |
Output is correct |
43 |
Correct |
16 ms |
23792 KB |
Output is correct |
44 |
Correct |
15 ms |
23808 KB |
Output is correct |
45 |
Correct |
15 ms |
23756 KB |
Output is correct |
46 |
Correct |
16 ms |
23888 KB |
Output is correct |
47 |
Correct |
15 ms |
23688 KB |
Output is correct |
48 |
Correct |
15 ms |
23832 KB |
Output is correct |
49 |
Correct |
16 ms |
23760 KB |
Output is correct |
50 |
Correct |
15 ms |
23700 KB |
Output is correct |
51 |
Correct |
17 ms |
23756 KB |
Output is correct |
52 |
Correct |
14 ms |
23756 KB |
Output is correct |
53 |
Correct |
16 ms |
23812 KB |
Output is correct |
54 |
Correct |
15 ms |
23732 KB |
Output is correct |
55 |
Correct |
16 ms |
23748 KB |
Output is correct |
56 |
Correct |
16 ms |
23804 KB |
Output is correct |
57 |
Correct |
15 ms |
23740 KB |
Output is correct |
58 |
Correct |
16 ms |
23940 KB |
Output is correct |
59 |
Correct |
508 ms |
45240 KB |
Output is correct |
60 |
Correct |
553 ms |
47796 KB |
Output is correct |
61 |
Correct |
16 ms |
23756 KB |
Output is correct |
62 |
Correct |
15 ms |
23756 KB |
Output is correct |
63 |
Correct |
412 ms |
43136 KB |
Output is correct |
64 |
Correct |
18 ms |
24268 KB |
Output is correct |
65 |
Correct |
29 ms |
26092 KB |
Output is correct |
66 |
Correct |
194 ms |
44240 KB |
Output is correct |
67 |
Correct |
693 ms |
64280 KB |
Output is correct |
68 |
Correct |
648 ms |
65360 KB |
Output is correct |
69 |
Correct |
22 ms |
24652 KB |
Output is correct |
70 |
Correct |
110 ms |
32192 KB |
Output is correct |
71 |
Correct |
361 ms |
48948 KB |
Output is correct |
72 |
Correct |
405 ms |
50096 KB |
Output is correct |
73 |
Correct |
128 ms |
30152 KB |
Output is correct |
74 |
Correct |
602 ms |
46616 KB |
Output is correct |
75 |
Correct |
41 ms |
26820 KB |
Output is correct |
76 |
Correct |
398 ms |
50468 KB |
Output is correct |
77 |
Correct |
366 ms |
48816 KB |
Output is correct |
78 |
Correct |
45 ms |
27332 KB |
Output is correct |
79 |
Correct |
663 ms |
61476 KB |
Output is correct |
80 |
Correct |
17 ms |
24012 KB |
Output is correct |
81 |
Correct |
155 ms |
32292 KB |
Output is correct |
82 |
Correct |
458 ms |
48776 KB |
Output is correct |
83 |
Correct |
600 ms |
46696 KB |
Output is correct |
84 |
Correct |
549 ms |
46644 KB |
Output is correct |
85 |
Correct |
546 ms |
46712 KB |
Output is correct |
86 |
Correct |
549 ms |
47704 KB |
Output is correct |
87 |
Correct |
627 ms |
47820 KB |
Output is correct |