#include <bits/stdc++.h>
#define foreach for
#define in :
using namespace std;
typedef long long ll;
/*
Konichiwa
Konichiwa
Ara ~~ ara
Bob no taisuki - Shinobu Kocho
* * * * *
* *
* *
* * I love SHINOBU <3 <3 <3
* *
* *
* * * * *
*/
/*
_________________________
Author : Bob15324
_________________________
*/
template<class X , class Y>
bool Minimize(X & x , Y y)
{
if(x == -1 || x >y)
{
x = y;
return true;
}
return false;
}
template<class X , class Y>
bool Maximize(X & x , Y y)
{
if( x < y)
{
x = y;
return true;
}
return false;
}
/* End of templates. Let's see what do we have here */
const int N = 5e5+1;
int n , deg[N] ;
vector<int>Leaves;
class GRAPH
{
private:
vector<vector<int>>vertices;
public :
GRAPH(int _n)
{
vertices.resize(_n+1);
}
void AddEdge(int u ,int v)
{
vertices[u].push_back(v);
vertices[v].push_back(u);
}
void DFS(int u ,int daddy)
{
if(deg[u] == 1)
{
Leaves.push_back(u);
}
foreach(int v in vertices[u])
{
if(v == daddy)
{
continue;
}
DFS(v , u);
}
}
};
int u ,v;
int main()
{
ios_base :: sync_with_stdio(0);cin.tie(0);
cin >> n;
GRAPH graph(n);
for(int i = 1; i <= n-1 ; i++)
{
cin >> u >> v;
graph.AddEdge(u , v);
deg[u]++;
deg[v]++;
}
graph.DFS(1 , -1);
cout << (((int)Leaves.size() + 1) >> 1) <<'\n' ;
for(int i = 0 ; i <= ((int)Leaves.size() >> 1) - 1 ; i++)
{
cout << Leaves[i] << ' ' << Leaves[i + ((int)Leaves.size() >> 1 )] <<'\n';
}
if(((int)Leaves.size() ) & 1)
{
cout << (int)Leaves[(int)Leaves.size()-1] << ' ' << (int)Leaves[((int)Leaves.size()) >> 1] <<'\n';
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
244 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
212 KB |
Output is correct |
9 |
Correct |
0 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Correct |
0 ms |
212 KB |
Output is correct |
16 |
Correct |
0 ms |
212 KB |
Output is correct |
17 |
Correct |
1 ms |
212 KB |
Output is correct |
18 |
Correct |
0 ms |
212 KB |
Output is correct |
19 |
Correct |
0 ms |
212 KB |
Output is correct |
20 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
244 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
212 KB |
Output is correct |
9 |
Correct |
0 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Correct |
0 ms |
212 KB |
Output is correct |
16 |
Correct |
0 ms |
212 KB |
Output is correct |
17 |
Correct |
1 ms |
212 KB |
Output is correct |
18 |
Correct |
0 ms |
212 KB |
Output is correct |
19 |
Correct |
0 ms |
212 KB |
Output is correct |
20 |
Correct |
1 ms |
212 KB |
Output is correct |
21 |
Correct |
1 ms |
320 KB |
Output is correct |
22 |
Correct |
1 ms |
468 KB |
Output is correct |
23 |
Correct |
1 ms |
428 KB |
Output is correct |
24 |
Correct |
1 ms |
468 KB |
Output is correct |
25 |
Correct |
1 ms |
468 KB |
Output is correct |
26 |
Correct |
1 ms |
336 KB |
Output is correct |
27 |
Correct |
1 ms |
468 KB |
Output is correct |
28 |
Correct |
1 ms |
468 KB |
Output is correct |
29 |
Correct |
1 ms |
340 KB |
Output is correct |
30 |
Correct |
0 ms |
212 KB |
Output is correct |
31 |
Correct |
1 ms |
468 KB |
Output is correct |
32 |
Correct |
1 ms |
212 KB |
Output is correct |
33 |
Correct |
1 ms |
212 KB |
Output is correct |
34 |
Correct |
0 ms |
212 KB |
Output is correct |
35 |
Correct |
0 ms |
212 KB |
Output is correct |
36 |
Correct |
1 ms |
324 KB |
Output is correct |
37 |
Correct |
1 ms |
336 KB |
Output is correct |
38 |
Correct |
1 ms |
340 KB |
Output is correct |
39 |
Correct |
1 ms |
212 KB |
Output is correct |
40 |
Correct |
1 ms |
212 KB |
Output is correct |
41 |
Correct |
1 ms |
328 KB |
Output is correct |
42 |
Correct |
1 ms |
328 KB |
Output is correct |
43 |
Correct |
1 ms |
340 KB |
Output is correct |
44 |
Correct |
1 ms |
212 KB |
Output is correct |
45 |
Correct |
1 ms |
340 KB |
Output is correct |
46 |
Correct |
1 ms |
340 KB |
Output is correct |
47 |
Correct |
1 ms |
212 KB |
Output is correct |
48 |
Correct |
1 ms |
340 KB |
Output is correct |
49 |
Correct |
1 ms |
340 KB |
Output is correct |
50 |
Correct |
1 ms |
212 KB |
Output is correct |
51 |
Correct |
0 ms |
212 KB |
Output is correct |
52 |
Correct |
1 ms |
324 KB |
Output is correct |
53 |
Correct |
1 ms |
340 KB |
Output is correct |
54 |
Correct |
1 ms |
212 KB |
Output is correct |
55 |
Correct |
1 ms |
340 KB |
Output is correct |
56 |
Correct |
1 ms |
212 KB |
Output is correct |
57 |
Correct |
1 ms |
340 KB |
Output is correct |
58 |
Correct |
1 ms |
468 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
244 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
212 KB |
Output is correct |
9 |
Correct |
0 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Correct |
0 ms |
212 KB |
Output is correct |
16 |
Correct |
0 ms |
212 KB |
Output is correct |
17 |
Correct |
1 ms |
212 KB |
Output is correct |
18 |
Correct |
0 ms |
212 KB |
Output is correct |
19 |
Correct |
0 ms |
212 KB |
Output is correct |
20 |
Correct |
1 ms |
212 KB |
Output is correct |
21 |
Correct |
1 ms |
320 KB |
Output is correct |
22 |
Correct |
1 ms |
468 KB |
Output is correct |
23 |
Correct |
1 ms |
428 KB |
Output is correct |
24 |
Correct |
1 ms |
468 KB |
Output is correct |
25 |
Correct |
1 ms |
468 KB |
Output is correct |
26 |
Correct |
1 ms |
336 KB |
Output is correct |
27 |
Correct |
1 ms |
468 KB |
Output is correct |
28 |
Correct |
1 ms |
468 KB |
Output is correct |
29 |
Correct |
1 ms |
340 KB |
Output is correct |
30 |
Correct |
0 ms |
212 KB |
Output is correct |
31 |
Correct |
1 ms |
468 KB |
Output is correct |
32 |
Correct |
1 ms |
212 KB |
Output is correct |
33 |
Correct |
1 ms |
212 KB |
Output is correct |
34 |
Correct |
0 ms |
212 KB |
Output is correct |
35 |
Correct |
0 ms |
212 KB |
Output is correct |
36 |
Correct |
1 ms |
324 KB |
Output is correct |
37 |
Correct |
1 ms |
336 KB |
Output is correct |
38 |
Correct |
1 ms |
340 KB |
Output is correct |
39 |
Correct |
1 ms |
212 KB |
Output is correct |
40 |
Correct |
1 ms |
212 KB |
Output is correct |
41 |
Correct |
1 ms |
328 KB |
Output is correct |
42 |
Correct |
1 ms |
328 KB |
Output is correct |
43 |
Correct |
1 ms |
340 KB |
Output is correct |
44 |
Correct |
1 ms |
212 KB |
Output is correct |
45 |
Correct |
1 ms |
340 KB |
Output is correct |
46 |
Correct |
1 ms |
340 KB |
Output is correct |
47 |
Correct |
1 ms |
212 KB |
Output is correct |
48 |
Correct |
1 ms |
340 KB |
Output is correct |
49 |
Correct |
1 ms |
340 KB |
Output is correct |
50 |
Correct |
1 ms |
212 KB |
Output is correct |
51 |
Correct |
0 ms |
212 KB |
Output is correct |
52 |
Correct |
1 ms |
324 KB |
Output is correct |
53 |
Correct |
1 ms |
340 KB |
Output is correct |
54 |
Correct |
1 ms |
212 KB |
Output is correct |
55 |
Correct |
1 ms |
340 KB |
Output is correct |
56 |
Correct |
1 ms |
212 KB |
Output is correct |
57 |
Correct |
1 ms |
340 KB |
Output is correct |
58 |
Correct |
1 ms |
468 KB |
Output is correct |
59 |
Correct |
326 ms |
36644 KB |
Output is correct |
60 |
Correct |
409 ms |
40692 KB |
Output is correct |
61 |
Correct |
1 ms |
212 KB |
Output is correct |
62 |
Correct |
1 ms |
212 KB |
Output is correct |
63 |
Correct |
279 ms |
32996 KB |
Output is correct |
64 |
Correct |
2 ms |
724 KB |
Output is correct |
65 |
Correct |
9 ms |
2572 KB |
Output is correct |
66 |
Correct |
128 ms |
18352 KB |
Output is correct |
67 |
Correct |
494 ms |
44620 KB |
Output is correct |
68 |
Correct |
467 ms |
45384 KB |
Output is correct |
69 |
Correct |
7 ms |
1620 KB |
Output is correct |
70 |
Correct |
88 ms |
13932 KB |
Output is correct |
71 |
Correct |
332 ms |
43820 KB |
Output is correct |
72 |
Correct |
338 ms |
42640 KB |
Output is correct |
73 |
Correct |
116 ms |
11124 KB |
Output is correct |
74 |
Correct |
459 ms |
39636 KB |
Output is correct |
75 |
Correct |
25 ms |
5044 KB |
Output is correct |
76 |
Correct |
347 ms |
43428 KB |
Output is correct |
77 |
Correct |
407 ms |
43516 KB |
Output is correct |
78 |
Correct |
27 ms |
4820 KB |
Output is correct |
79 |
Correct |
512 ms |
43476 KB |
Output is correct |
80 |
Correct |
2 ms |
596 KB |
Output is correct |
81 |
Correct |
104 ms |
14240 KB |
Output is correct |
82 |
Correct |
390 ms |
41512 KB |
Output is correct |
83 |
Correct |
450 ms |
39528 KB |
Output is correct |
84 |
Correct |
539 ms |
39528 KB |
Output is correct |
85 |
Correct |
482 ms |
39620 KB |
Output is correct |
86 |
Correct |
478 ms |
40668 KB |
Output is correct |
87 |
Correct |
476 ms |
40608 KB |
Output is correct |