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Submission #335635

# Submission time Handle Problem Language Result Execution time Memory
335635 2020-12-13T12:16:04 Z Joshc Network (BOI15_net) C++11
100 / 100
 542 ms 52328 KB 
#include <cstdio>
#include <vector>
using namespace std;

vector<int> edges[500001], l;

void dfs(int v, int p) {
    if (edges[v].size() == 1) l.push_back(v);
    for (int u : edges[v]) {
        if (u != p) dfs(u, v);
    }
}

int main() {
    int n, a, b;
    scanf("%d", &n);
    for (int i=1; i<n; i++) {
        scanf("%d%d", &a, &b);
        edges[a].push_back(b);
        edges[b].push_back(a);
    }
    dfs(1, 0);
    int s = (l.size()+1)>>1;
    printf("%d\n", s);
    for (int i=0; i<s; i++) printf("%d %d\n", l[i], l[(i+s)%l.size()]);
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:16:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   16 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
net.cpp:18:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   18 |         scanf("%d%d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12012 KB Output is correct
2 Correct 9 ms 12012 KB Output is correct
3 Correct 8 ms 12012 KB Output is correct
4 Correct 8 ms 12012 KB Output is correct
5 Correct 8 ms 12012 KB Output is correct
6 Correct 9 ms 12012 KB Output is correct
7 Correct 9 ms 12012 KB Output is correct
8 Correct 8 ms 12012 KB Output is correct
9 Correct 10 ms 12032 KB Output is correct
10 Correct 8 ms 12012 KB Output is correct
11 Correct 9 ms 12012 KB Output is correct
12 Correct 8 ms 12012 KB Output is correct
13 Correct 8 ms 12012 KB Output is correct
14 Correct 9 ms 12032 KB Output is correct
15 Correct 8 ms 12012 KB Output is correct
16 Correct 8 ms 12012 KB Output is correct
17 Correct 8 ms 12012 KB Output is correct
18 Correct 9 ms 12012 KB Output is correct
19 Correct 8 ms 12012 KB Output is correct
20 Correct 9 ms 12024 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12012 KB Output is correct
2 Correct 9 ms 12012 KB Output is correct
3 Correct 8 ms 12012 KB Output is correct
4 Correct 8 ms 12012 KB Output is correct
5 Correct 8 ms 12012 KB Output is correct
6 Correct 9 ms 12012 KB Output is correct
7 Correct 9 ms 12012 KB Output is correct
8 Correct 8 ms 12012 KB Output is correct
9 Correct 10 ms 12032 KB Output is correct
10 Correct 8 ms 12012 KB Output is correct
11 Correct 9 ms 12012 KB Output is correct
12 Correct 8 ms 12012 KB Output is correct
13 Correct 8 ms 12012 KB Output is correct
14 Correct 9 ms 12032 KB Output is correct
15 Correct 8 ms 12012 KB Output is correct
16 Correct 8 ms 12012 KB Output is correct
17 Correct 8 ms 12012 KB Output is correct
18 Correct 9 ms 12012 KB Output is correct
19 Correct 8 ms 12012 KB Output is correct
20 Correct 9 ms 12024 KB Output is correct
21 Correct 9 ms 12140 KB Output is correct
22 Correct 9 ms 12140 KB Output is correct
23 Correct 9 ms 12140 KB Output is correct
24 Correct 10 ms 12140 KB Output is correct
25 Correct 9 ms 12140 KB Output is correct
26 Correct 11 ms 12140 KB Output is correct
27 Correct 11 ms 12140 KB Output is correct
28 Correct 9 ms 12140 KB Output is correct
29 Correct 9 ms 12140 KB Output is correct
30 Correct 8 ms 12012 KB Output is correct
31 Correct 9 ms 12140 KB Output is correct
32 Correct 8 ms 12012 KB Output is correct
33 Correct 8 ms 12012 KB Output is correct
34 Correct 9 ms 12012 KB Output is correct
35 Correct 9 ms 12032 KB Output is correct
36 Correct 8 ms 12012 KB Output is correct
37 Correct 8 ms 12140 KB Output is correct
38 Correct 9 ms 12140 KB Output is correct
39 Correct 9 ms 12012 KB Output is correct
40 Correct 9 ms 12012 KB Output is correct
41 Correct 8 ms 12032 KB Output is correct
42 Correct 9 ms 12012 KB Output is correct
43 Correct 9 ms 12140 KB Output is correct
44 Correct 8 ms 12012 KB Output is correct
45 Correct 9 ms 12032 KB Output is correct
46 Correct 9 ms 12140 KB Output is correct
47 Correct 9 ms 12012 KB Output is correct
48 Correct 9 ms 12012 KB Output is correct
49 Correct 9 ms 12140 KB Output is correct
50 Correct 8 ms 12012 KB Output is correct
51 Correct 8 ms 12012 KB Output is correct
52 Correct 9 ms 12012 KB Output is correct
53 Correct 10 ms 12140 KB Output is correct
54 Correct 8 ms 12012 KB Output is correct
55 Correct 9 ms 12012 KB Output is correct
56 Correct 9 ms 12012 KB Output is correct
57 Correct 10 ms 12012 KB Output is correct
58 Correct 10 ms 12140 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12012 KB Output is correct
2 Correct 9 ms 12012 KB Output is correct
3 Correct 8 ms 12012 KB Output is correct
4 Correct 8 ms 12012 KB Output is correct
5 Correct 8 ms 12012 KB Output is correct
6 Correct 9 ms 12012 KB Output is correct
7 Correct 9 ms 12012 KB Output is correct
8 Correct 8 ms 12012 KB Output is correct
9 Correct 10 ms 12032 KB Output is correct
10 Correct 8 ms 12012 KB Output is correct
11 Correct 9 ms 12012 KB Output is correct
12 Correct 8 ms 12012 KB Output is correct
13 Correct 8 ms 12012 KB Output is correct
14 Correct 9 ms 12032 KB Output is correct
15 Correct 8 ms 12012 KB Output is correct
16 Correct 8 ms 12012 KB Output is correct
17 Correct 8 ms 12012 KB Output is correct
18 Correct 9 ms 12012 KB Output is correct
19 Correct 8 ms 12012 KB Output is correct
20 Correct 9 ms 12024 KB Output is correct
21 Correct 9 ms 12140 KB Output is correct
22 Correct 9 ms 12140 KB Output is correct
23 Correct 9 ms 12140 KB Output is correct
24 Correct 10 ms 12140 KB Output is correct
25 Correct 9 ms 12140 KB Output is correct
26 Correct 11 ms 12140 KB Output is correct
27 Correct 11 ms 12140 KB Output is correct
28 Correct 9 ms 12140 KB Output is correct
29 Correct 9 ms 12140 KB Output is correct
30 Correct 8 ms 12012 KB Output is correct
31 Correct 9 ms 12140 KB Output is correct
32 Correct 8 ms 12012 KB Output is correct
33 Correct 8 ms 12012 KB Output is correct
34 Correct 9 ms 12012 KB Output is correct
35 Correct 9 ms 12032 KB Output is correct
36 Correct 8 ms 12012 KB Output is correct
37 Correct 8 ms 12140 KB Output is correct
38 Correct 9 ms 12140 KB Output is correct
39 Correct 9 ms 12012 KB Output is correct
40 Correct 9 ms 12012 KB Output is correct
41 Correct 8 ms 12032 KB Output is correct
42 Correct 9 ms 12012 KB Output is correct
43 Correct 9 ms 12140 KB Output is correct
44 Correct 8 ms 12012 KB Output is correct
45 Correct 9 ms 12032 KB Output is correct
46 Correct 9 ms 12140 KB Output is correct
47 Correct 9 ms 12012 KB Output is correct
48 Correct 9 ms 12012 KB Output is correct
49 Correct 9 ms 12140 KB Output is correct
50 Correct 8 ms 12012 KB Output is correct
51 Correct 8 ms 12012 KB Output is correct
52 Correct 9 ms 12012 KB Output is correct
53 Correct 10 ms 12140 KB Output is correct
54 Correct 8 ms 12012 KB Output is correct
55 Correct 9 ms 12012 KB Output is correct
56 Correct 9 ms 12012 KB Output is correct
57 Correct 10 ms 12012 KB Output is correct
58 Correct 10 ms 12140 KB Output is correct
59 Correct 408 ms 36196 KB Output is correct
60 Correct 500 ms 38844 KB Output is correct
61 Correct 8 ms 12012 KB Output is correct
62 Correct 8 ms 12012 KB Output is correct
63 Correct 360 ms 33632 KB Output is correct
64 Correct 11 ms 12524 KB Output is correct
65 Correct 20 ms 14188 KB Output is correct
66 Correct 168 ms 30572 KB Output is correct
67 Correct 542 ms 51052 KB Output is correct
68 Correct 542 ms 52328 KB Output is correct
69 Correct 17 ms 12908 KB Output is correct
70 Correct 107 ms 21220 KB Output is correct
71 Correct 352 ms 41948 KB Output is correct
72 Correct 378 ms 40844 KB Output is correct
73 Correct 120 ms 19172 KB Output is correct
74 Correct 504 ms 37860 KB Output is correct
75 Correct 36 ms 15212 KB Output is correct
76 Correct 362 ms 41548 KB Output is correct
77 Correct 360 ms 41676 KB Output is correct
78 Correct 39 ms 15596 KB Output is correct
79 Correct 536 ms 48988 KB Output is correct
80 Correct 10 ms 12268 KB Output is correct
81 Correct 133 ms 21348 KB Output is correct
82 Correct 432 ms 39648 KB Output is correct
83 Correct 496 ms 37732 KB Output is correct
84 Correct 497 ms 37772 KB Output is correct
85 Correct 498 ms 37872 KB Output is correct
86 Correct 503 ms 38904 KB Output is correct
87 Correct 492 ms 38752 KB Output is correct