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Submission #790126

# Submission time Handle Problem Language Result Execution time Memory
790126 2023-07-22T10:52:21 Z tch1cherin Network (BOI15_net) C++17
100 / 100
 610 ms 51968 KB 
#include <bits/stdc++.h>
using namespace std;

const int MAX_N = 500005;
vector<int> G[MAX_N];
vector<int> ord;

void DFS(int u, int p) {
  for (int v : G[u]) {
    if (v != p) {
      DFS(v, u);
    }
  }
  if (G[u].size() == 1) {
    ord.push_back(u);
  }
}

int main() {
  int N;
  cin >> N;
  for (int i = 0; i < N - 1; i++) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    G[u].push_back(v);
    G[v].push_back(u);
  }
  DFS(0, -1);
  int L = (int)ord.size();
  cout << (L + 1) / 2 << "\n";
  for (int i = 0; i < (L + 1) / 2; i++) {
    cout << 1 + ord[i] << " " << 1 + ord[i + L / 2] << "\n";
  }
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 12032 KB Output is correct
2 Correct 6 ms 11988 KB Output is correct
3 Correct 6 ms 11948 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 8 ms 11964 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 12048 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 7 ms 11988 KB Output is correct
10 Correct 6 ms 12040 KB Output is correct
11 Correct 7 ms 11988 KB Output is correct
12 Correct 6 ms 12044 KB Output is correct
13 Correct 6 ms 12040 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 5 ms 11988 KB Output is correct
17 Correct 8 ms 12048 KB Output is correct
18 Correct 6 ms 12044 KB Output is correct
19 Correct 7 ms 12040 KB Output is correct
20 Correct 6 ms 12040 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 12032 KB Output is correct
2 Correct 6 ms 11988 KB Output is correct
3 Correct 6 ms 11948 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 8 ms 11964 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 12048 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 7 ms 11988 KB Output is correct
10 Correct 6 ms 12040 KB Output is correct
11 Correct 7 ms 11988 KB Output is correct
12 Correct 6 ms 12044 KB Output is correct
13 Correct 6 ms 12040 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 5 ms 11988 KB Output is correct
17 Correct 8 ms 12048 KB Output is correct
18 Correct 6 ms 12044 KB Output is correct
19 Correct 7 ms 12040 KB Output is correct
20 Correct 6 ms 12040 KB Output is correct
21 Correct 6 ms 11992 KB Output is correct
22 Correct 7 ms 12116 KB Output is correct
23 Correct 8 ms 12056 KB Output is correct
24 Correct 6 ms 12060 KB Output is correct
25 Correct 7 ms 12052 KB Output is correct
26 Correct 6 ms 12116 KB Output is correct
27 Correct 6 ms 12116 KB Output is correct
28 Correct 6 ms 12056 KB Output is correct
29 Correct 7 ms 12160 KB Output is correct
30 Correct 7 ms 12048 KB Output is correct
31 Correct 6 ms 12072 KB Output is correct
32 Correct 6 ms 11988 KB Output is correct
33 Correct 6 ms 11988 KB Output is correct
34 Correct 6 ms 11988 KB Output is correct
35 Correct 6 ms 12000 KB Output is correct
36 Correct 6 ms 12040 KB Output is correct
37 Correct 6 ms 11988 KB Output is correct
38 Correct 7 ms 12044 KB Output is correct
39 Correct 6 ms 11988 KB Output is correct
40 Correct 6 ms 11988 KB Output is correct
41 Correct 6 ms 11988 KB Output is correct
42 Correct 6 ms 11972 KB Output is correct
43 Correct 6 ms 12052 KB Output is correct
44 Correct 6 ms 11988 KB Output is correct
45 Correct 6 ms 11988 KB Output is correct
46 Correct 6 ms 11988 KB Output is correct
47 Correct 7 ms 12044 KB Output is correct
48 Correct 6 ms 11988 KB Output is correct
49 Correct 6 ms 11988 KB Output is correct
50 Correct 6 ms 11988 KB Output is correct
51 Correct 6 ms 12044 KB Output is correct
52 Correct 7 ms 11988 KB Output is correct
53 Correct 6 ms 11988 KB Output is correct
54 Correct 5 ms 11988 KB Output is correct
55 Correct 6 ms 12040 KB Output is correct
56 Correct 6 ms 11988 KB Output is correct
57 Correct 7 ms 11988 KB Output is correct
58 Correct 7 ms 12116 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 12032 KB Output is correct
2 Correct 6 ms 11988 KB Output is correct
3 Correct 6 ms 11948 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 8 ms 11964 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 12048 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 7 ms 11988 KB Output is correct
10 Correct 6 ms 12040 KB Output is correct
11 Correct 7 ms 11988 KB Output is correct
12 Correct 6 ms 12044 KB Output is correct
13 Correct 6 ms 12040 KB Output is correct
14 Correct 6 ms 11988 KB Output is correct
15 Correct 6 ms 11988 KB Output is correct
16 Correct 5 ms 11988 KB Output is correct
17 Correct 8 ms 12048 KB Output is correct
18 Correct 6 ms 12044 KB Output is correct
19 Correct 7 ms 12040 KB Output is correct
20 Correct 6 ms 12040 KB Output is correct
21 Correct 6 ms 11992 KB Output is correct
22 Correct 7 ms 12116 KB Output is correct
23 Correct 8 ms 12056 KB Output is correct
24 Correct 6 ms 12060 KB Output is correct
25 Correct 7 ms 12052 KB Output is correct
26 Correct 6 ms 12116 KB Output is correct
27 Correct 6 ms 12116 KB Output is correct
28 Correct 6 ms 12056 KB Output is correct
29 Correct 7 ms 12160 KB Output is correct
30 Correct 7 ms 12048 KB Output is correct
31 Correct 6 ms 12072 KB Output is correct
32 Correct 6 ms 11988 KB Output is correct
33 Correct 6 ms 11988 KB Output is correct
34 Correct 6 ms 11988 KB Output is correct
35 Correct 6 ms 12000 KB Output is correct
36 Correct 6 ms 12040 KB Output is correct
37 Correct 6 ms 11988 KB Output is correct
38 Correct 7 ms 12044 KB Output is correct
39 Correct 6 ms 11988 KB Output is correct
40 Correct 6 ms 11988 KB Output is correct
41 Correct 6 ms 11988 KB Output is correct
42 Correct 6 ms 11972 KB Output is correct
43 Correct 6 ms 12052 KB Output is correct
44 Correct 6 ms 11988 KB Output is correct
45 Correct 6 ms 11988 KB Output is correct
46 Correct 6 ms 11988 KB Output is correct
47 Correct 7 ms 12044 KB Output is correct
48 Correct 6 ms 11988 KB Output is correct
49 Correct 6 ms 11988 KB Output is correct
50 Correct 6 ms 11988 KB Output is correct
51 Correct 6 ms 12044 KB Output is correct
52 Correct 7 ms 11988 KB Output is correct
53 Correct 6 ms 11988 KB Output is correct
54 Correct 5 ms 11988 KB Output is correct
55 Correct 6 ms 12040 KB Output is correct
56 Correct 6 ms 11988 KB Output is correct
57 Correct 7 ms 11988 KB Output is correct
58 Correct 7 ms 12116 KB Output is correct
59 Correct 376 ms 35932 KB Output is correct
60 Correct 446 ms 38764 KB Output is correct
61 Correct 6 ms 11988 KB Output is correct
62 Correct 7 ms 11960 KB Output is correct
63 Correct 318 ms 33548 KB Output is correct
64 Correct 9 ms 12500 KB Output is correct
65 Correct 19 ms 14180 KB Output is correct
66 Correct 127 ms 30524 KB Output is correct
67 Correct 523 ms 51020 KB Output is correct
68 Correct 520 ms 51968 KB Output is correct
69 Correct 13 ms 12820 KB Output is correct
70 Correct 104 ms 21216 KB Output is correct
71 Correct 421 ms 41824 KB Output is correct
72 Correct 393 ms 40612 KB Output is correct
73 Correct 98 ms 19036 KB Output is correct
74 Correct 499 ms 37652 KB Output is correct
75 Correct 39 ms 15236 KB Output is correct
76 Correct 379 ms 41532 KB Output is correct
77 Correct 403 ms 41524 KB Output is correct
78 Correct 44 ms 15584 KB Output is correct
79 Correct 610 ms 48696 KB Output is correct
80 Correct 10 ms 12268 KB Output is correct
81 Correct 138 ms 21168 KB Output is correct
82 Correct 475 ms 39476 KB Output is correct
83 Correct 477 ms 37640 KB Output is correct
84 Correct 468 ms 37620 KB Output is correct
85 Correct 462 ms 37584 KB Output is correct
86 Correct 469 ms 38748 KB Output is correct
87 Correct 436 ms 38696 KB Output is correct