답안 #30481 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
30481	2017-07-23T19:07:35 Z	sampriti	Network (BOI15_net)	C++14	63 / 100	439 ms	32100 KB

#include <iostream>
#include <algorithm>
#include <vector>
#include <cassert>

using namespace std;

vector<int> G[500001];
vector<int> leaves;

void dfs(int i, int p) {
  if(G[i].size() == 1) leaves.push_back(i);

  for(int j = 0; j < G[i].size(); j++) {
    int u = G[i][j];
    if(u == p) continue;
    dfs(u, i);
  }
}

int main() {
  ios::sync_with_stdio(false); cin.tie(0);

  int N; cin >> N;

  for(int i = 0; i < N - 1; i++) {
    int a, b; cin >> a >> b;
    G[a].push_back(b);
    G[b].push_back(a);
  }

  dfs(1, 0);

  int ans = (leaves.size() + 1)/2;

  cout << ans << endl;

  for(int i = 0; i < ans; i++) {
    assert((i + leaves.size()/2) < leaves.size());
    cout << leaves[i] << " " << leaves[i + leaves.size()/2] << endl;
  }
}

Compilation message

net.cpp: In function 'void dfs(int, int)':
net.cpp:14:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = 0; j < G[i].size(); j++) {
                    ^

Subtask #1
18.0 / 18.0

#	결과	실행 시간	메모리	Grader output
1	Correct	3 ms	13896 KB	Output is correct
2	Correct	3 ms	13896 KB	Output is correct
3	Correct	0 ms	13896 KB	Output is correct
4	Correct	0 ms	13896 KB	Output is correct
5	Correct	3 ms	13896 KB	Output is correct
6	Correct	0 ms	13896 KB	Output is correct
7	Correct	6 ms	13896 KB	Output is correct
8	Correct	3 ms	13896 KB	Output is correct
9	Correct	3 ms	13896 KB	Output is correct
10	Correct	0 ms	13896 KB	Output is correct
11	Correct	3 ms	13896 KB	Output is correct
12	Correct	0 ms	13896 KB	Output is correct
13	Correct	6 ms	13896 KB	Output is correct
14	Correct	3 ms	13896 KB	Output is correct
15	Correct	0 ms	13896 KB	Output is correct
16	Correct	3 ms	13896 KB	Output is correct
17	Correct	3 ms	13896 KB	Output is correct
18	Correct	3 ms	13896 KB	Output is correct
19	Correct	0 ms	13896 KB	Output is correct
20	Correct	3 ms	13896 KB	Output is correct

Subtask #2
45.0 / 45.0

#	결과	실행 시간	메모리	Grader output
1	Correct	3 ms	13896 KB	Output is correct
2	Correct	3 ms	13896 KB	Output is correct
3	Correct	0 ms	13896 KB	Output is correct
4	Correct	0 ms	13896 KB	Output is correct
5	Correct	3 ms	13896 KB	Output is correct
6	Correct	0 ms	13896 KB	Output is correct
7	Correct	6 ms	13896 KB	Output is correct
8	Correct	3 ms	13896 KB	Output is correct
9	Correct	3 ms	13896 KB	Output is correct
10	Correct	0 ms	13896 KB	Output is correct
11	Correct	3 ms	13896 KB	Output is correct
12	Correct	0 ms	13896 KB	Output is correct
13	Correct	6 ms	13896 KB	Output is correct
14	Correct	3 ms	13896 KB	Output is correct
15	Correct	0 ms	13896 KB	Output is correct
16	Correct	3 ms	13896 KB	Output is correct
17	Correct	3 ms	13896 KB	Output is correct
18	Correct	3 ms	13896 KB	Output is correct
19	Correct	0 ms	13896 KB	Output is correct
20	Correct	3 ms	13896 KB	Output is correct
21	Correct	0 ms	13896 KB	Output is correct
22	Correct	6 ms	13896 KB	Output is correct
23	Correct	6 ms	13896 KB	Output is correct
24	Correct	6 ms	13896 KB	Output is correct
25	Correct	6 ms	13896 KB	Output is correct
26	Correct	3 ms	13896 KB	Output is correct
27	Correct	6 ms	13896 KB	Output is correct
28	Correct	13 ms	13896 KB	Output is correct
29	Correct	6 ms	13896 KB	Output is correct
30	Correct	0 ms	13896 KB	Output is correct
31	Correct	3 ms	13896 KB	Output is correct
32	Correct	0 ms	13896 KB	Output is correct
33	Correct	0 ms	13896 KB	Output is correct
34	Correct	3 ms	13896 KB	Output is correct
35	Correct	3 ms	13896 KB	Output is correct
36	Correct	0 ms	13896 KB	Output is correct
37	Correct	0 ms	13896 KB	Output is correct
38	Correct	0 ms	13896 KB	Output is correct
39	Correct	3 ms	13896 KB	Output is correct
40	Correct	6 ms	13896 KB	Output is correct
41	Correct	0 ms	13896 KB	Output is correct
42	Correct	3 ms	13896 KB	Output is correct
43	Correct	3 ms	13896 KB	Output is correct
44	Correct	3 ms	13896 KB	Output is correct
45	Correct	3 ms	13896 KB	Output is correct
46	Correct	9 ms	13896 KB	Output is correct
47	Correct	3 ms	13896 KB	Output is correct
48	Correct	3 ms	13896 KB	Output is correct
49	Correct	3 ms	13896 KB	Output is correct
50	Correct	9 ms	13896 KB	Output is correct
51	Correct	3 ms	13896 KB	Output is correct
52	Correct	3 ms	13896 KB	Output is correct
53	Correct	0 ms	13896 KB	Output is correct
54	Correct	3 ms	13896 KB	Output is correct
55	Correct	3 ms	13896 KB	Output is correct
56	Correct	0 ms	13896 KB	Output is correct
57	Correct	3 ms	13896 KB	Output is correct
58	Correct	9 ms	13896 KB	Output is correct

Subtask #3
0 / 37.0

#	결과	실행 시간	메모리	Grader output
1	Correct	3 ms	13896 KB	Output is correct
2	Correct	3 ms	13896 KB	Output is correct
3	Correct	0 ms	13896 KB	Output is correct
4	Correct	0 ms	13896 KB	Output is correct
5	Correct	3 ms	13896 KB	Output is correct
6	Correct	0 ms	13896 KB	Output is correct
7	Correct	6 ms	13896 KB	Output is correct
8	Correct	3 ms	13896 KB	Output is correct
9	Correct	3 ms	13896 KB	Output is correct
10	Correct	0 ms	13896 KB	Output is correct
11	Correct	3 ms	13896 KB	Output is correct
12	Correct	0 ms	13896 KB	Output is correct
13	Correct	6 ms	13896 KB	Output is correct
14	Correct	3 ms	13896 KB	Output is correct
15	Correct	0 ms	13896 KB	Output is correct
16	Correct	3 ms	13896 KB	Output is correct
17	Correct	3 ms	13896 KB	Output is correct
18	Correct	3 ms	13896 KB	Output is correct
19	Correct	0 ms	13896 KB	Output is correct
20	Correct	3 ms	13896 KB	Output is correct
21	Correct	0 ms	13896 KB	Output is correct
22	Correct	6 ms	13896 KB	Output is correct
23	Correct	6 ms	13896 KB	Output is correct
24	Correct	6 ms	13896 KB	Output is correct
25	Correct	6 ms	13896 KB	Output is correct
26	Correct	3 ms	13896 KB	Output is correct
27	Correct	6 ms	13896 KB	Output is correct
28	Correct	13 ms	13896 KB	Output is correct
29	Correct	6 ms	13896 KB	Output is correct
30	Correct	0 ms	13896 KB	Output is correct
31	Correct	3 ms	13896 KB	Output is correct
32	Correct	0 ms	13896 KB	Output is correct
33	Correct	0 ms	13896 KB	Output is correct
34	Correct	3 ms	13896 KB	Output is correct
35	Correct	3 ms	13896 KB	Output is correct
36	Correct	0 ms	13896 KB	Output is correct
37	Correct	0 ms	13896 KB	Output is correct
38	Correct	0 ms	13896 KB	Output is correct
39	Correct	3 ms	13896 KB	Output is correct
40	Correct	6 ms	13896 KB	Output is correct
41	Correct	0 ms	13896 KB	Output is correct
42	Correct	3 ms	13896 KB	Output is correct
43	Correct	3 ms	13896 KB	Output is correct
44	Correct	3 ms	13896 KB	Output is correct
45	Correct	3 ms	13896 KB	Output is correct
46	Correct	9 ms	13896 KB	Output is correct
47	Correct	3 ms	13896 KB	Output is correct
48	Correct	3 ms	13896 KB	Output is correct
49	Correct	3 ms	13896 KB	Output is correct
50	Correct	9 ms	13896 KB	Output is correct
51	Correct	3 ms	13896 KB	Output is correct
52	Correct	3 ms	13896 KB	Output is correct
53	Correct	0 ms	13896 KB	Output is correct
54	Correct	3 ms	13896 KB	Output is correct
55	Correct	3 ms	13896 KB	Output is correct
56	Correct	0 ms	13896 KB	Output is correct
57	Correct	3 ms	13896 KB	Output is correct
58	Correct	9 ms	13896 KB	Output is correct
59	Runtime error	439 ms	32100 KB	Execution timed out (wall clock limit exceeded)
60	Halted	0 ms	0 KB	-

답안 #30481

Compilation message

Subtask #1 18.0 / 18.0

Subtask #2 45.0 / 45.0

Subtask #3 0 / 37.0

Subtask #1
18.0 / 18.0

Subtask #2
45.0 / 45.0

Subtask #3
0 / 37.0