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Submission #320884

# Submission time Handle Problem Language Result Execution time Memory
320884 2020-11-10T06:49:37 Z gustason Network (BOI15_net) C++14
100 / 100
 519 ms 52192 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int maxN = 500005;
vector<int> adj[maxN], leafs;
void dfs(int v, int par) {
    if (adj[v].size() == 1) {
        leafs.push_back(v);
    }
    for(int u : adj[v]) {
        if (u != par) {
            dfs(u, v);
        }
    }
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    for(int i = 0; i < n-1; i++) {
        int a, b;
        cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    dfs(1, -1);
    int ls = leafs.size();
    if (ls % 2 == 0) {
        cout << ls / 2 << "\n";
        for(int i = 0; i < ls/2; i++) {
            cout << leafs[i] << " " << leafs[ls/2+i] << "\n";
        }
    } else {
        cout << ls / 2 + 1 << "\n";
        for(int i = 0; i < ls/2; i++) {
            cout << leafs[i] << " " << leafs[ls/2+i] << "\n";
        }
        cout << leafs.back() << " " << leafs[ls/2];
    }
    return 0;
}
//~ check for overflows

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 12012 KB Output is correct
2 Correct 8 ms 12012 KB Output is correct
3 Correct 8 ms 12140 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 8 ms 12012 KB Output is correct
8 Correct 8 ms 12012 KB Output is correct
9 Correct 8 ms 12012 KB Output is correct
10 Correct 8 ms 12012 KB Output is correct
11 Correct 10 ms 12012 KB Output is correct
12 Correct 9 ms 12160 KB Output is correct
13 Correct 8 ms 12012 KB Output is correct
14 Correct 9 ms 12012 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 12140 KB Output is correct
20 Correct 9 ms 12012 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 12012 KB Output is correct
2 Correct 8 ms 12012 KB Output is correct
3 Correct 8 ms 12140 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 8 ms 12012 KB Output is correct
8 Correct 8 ms 12012 KB Output is correct
9 Correct 8 ms 12012 KB Output is correct
10 Correct 8 ms 12012 KB Output is correct
11 Correct 10 ms 12012 KB Output is correct
12 Correct 9 ms 12160 KB Output is correct
13 Correct 8 ms 12012 KB Output is correct
14 Correct 9 ms 12012 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 12140 KB Output is correct
20 Correct 9 ms 12012 KB Output is correct
21 Correct 9 ms 12012 KB Output is correct
22 Correct 9 ms 12140 KB Output is correct
23 Correct 9 ms 12140 KB Output is correct
24 Correct 9 ms 12140 KB Output is correct
25 Correct 9 ms 12140 KB Output is correct
26 Correct 9 ms 12140 KB Output is correct
27 Correct 9 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 12140 KB Output is correct
31 Correct 9 ms 12140 KB Output is correct
32 Correct 10 ms 12012 KB Output is correct
33 Correct 9 ms 12012 KB Output is correct
34 Correct 8 ms 12140 KB Output is correct
35 Correct 9 ms 12012 KB Output is correct
36 Correct 9 ms 12140 KB Output is correct
37 Correct 9 ms 12140 KB Output is correct
38 Correct 9 ms 12140 KB Output is correct
39 Correct 8 ms 12012 KB Output is correct
40 Correct 8 ms 12140 KB Output is correct
41 Correct 9 ms 12140 KB Output is correct
42 Correct 9 ms 12140 KB Output is correct
43 Correct 9 ms 12140 KB Output is correct
44 Correct 8 ms 12140 KB Output is correct
45 Correct 10 ms 12140 KB Output is correct
46 Correct 9 ms 12268 KB Output is correct
47 Correct 8 ms 12140 KB Output is correct
48 Correct 9 ms 12140 KB Output is correct
49 Correct 9 ms 12140 KB Output is correct
50 Correct 9 ms 12012 KB Output is correct
51 Correct 9 ms 12140 KB Output is correct
52 Correct 9 ms 12140 KB Output is correct
53 Correct 9 ms 12148 KB Output is correct
54 Correct 11 ms 12012 KB Output is correct
55 Correct 9 ms 12140 KB Output is correct
56 Correct 8 ms 12140 KB Output is correct
57 Correct 9 ms 12140 KB Output is correct
58 Correct 9 ms 12396 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 12012 KB Output is correct
2 Correct 8 ms 12012 KB Output is correct
3 Correct 8 ms 12140 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 8 ms 12012 KB Output is correct
8 Correct 8 ms 12012 KB Output is correct
9 Correct 8 ms 12012 KB Output is correct
10 Correct 8 ms 12012 KB Output is correct
11 Correct 10 ms 12012 KB Output is correct
12 Correct 9 ms 12160 KB Output is correct
13 Correct 8 ms 12012 KB Output is correct
14 Correct 9 ms 12012 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 12140 KB Output is correct
20 Correct 9 ms 12012 KB Output is correct
21 Correct 9 ms 12012 KB Output is correct
22 Correct 9 ms 12140 KB Output is correct
23 Correct 9 ms 12140 KB Output is correct
24 Correct 9 ms 12140 KB Output is correct
25 Correct 9 ms 12140 KB Output is correct
26 Correct 9 ms 12140 KB Output is correct
27 Correct 9 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 12140 KB Output is correct
31 Correct 9 ms 12140 KB Output is correct
32 Correct 10 ms 12012 KB Output is correct
33 Correct 9 ms 12012 KB Output is correct
34 Correct 8 ms 12140 KB Output is correct
35 Correct 9 ms 12012 KB Output is correct
36 Correct 9 ms 12140 KB Output is correct
37 Correct 9 ms 12140 KB Output is correct
38 Correct 9 ms 12140 KB Output is correct
39 Correct 8 ms 12012 KB Output is correct
40 Correct 8 ms 12140 KB Output is correct
41 Correct 9 ms 12140 KB Output is correct
42 Correct 9 ms 12140 KB Output is correct
43 Correct 9 ms 12140 KB Output is correct
44 Correct 8 ms 12140 KB Output is correct
45 Correct 10 ms 12140 KB Output is correct
46 Correct 9 ms 12268 KB Output is correct
47 Correct 8 ms 12140 KB Output is correct
48 Correct 9 ms 12140 KB Output is correct
49 Correct 9 ms 12140 KB Output is correct
50 Correct 9 ms 12012 KB Output is correct
51 Correct 9 ms 12140 KB Output is correct
52 Correct 9 ms 12140 KB Output is correct
53 Correct 9 ms 12148 KB Output is correct
54 Correct 11 ms 12012 KB Output is correct
55 Correct 9 ms 12140 KB Output is correct
56 Correct 8 ms 12140 KB Output is correct
57 Correct 9 ms 12140 KB Output is correct
58 Correct 9 ms 12396 KB Output is correct
59 Correct 396 ms 36176 KB Output is correct
60 Correct 461 ms 38868 KB Output is correct
61 Correct 11 ms 12288 KB Output is correct
62 Correct 8 ms 12012 KB Output is correct
63 Correct 345 ms 33796 KB Output is correct
64 Correct 10 ms 12800 KB Output is correct
65 Correct 20 ms 14316 KB Output is correct
66 Correct 169 ms 30656 KB Output is correct
67 Correct 513 ms 51364 KB Output is correct
68 Correct 512 ms 52192 KB Output is correct
69 Correct 15 ms 13036 KB Output is correct
70 Correct 99 ms 21340 KB Output is correct
71 Correct 328 ms 42196 KB Output is correct
72 Correct 340 ms 40912 KB Output is correct
73 Correct 109 ms 19172 KB Output is correct
74 Correct 466 ms 37844 KB Output is correct
75 Correct 33 ms 15340 KB Output is correct
76 Correct 335 ms 41660 KB Output is correct
77 Correct 331 ms 42068 KB Output is correct
78 Correct 34 ms 15716 KB Output is correct
79 Correct 519 ms 48868 KB Output is correct
80 Correct 10 ms 12268 KB Output is correct
81 Correct 116 ms 21356 KB Output is correct
82 Correct 407 ms 39768 KB Output is correct
83 Correct 462 ms 37700 KB Output is correct
84 Correct 499 ms 37876 KB Output is correct
85 Correct 486 ms 37716 KB Output is correct
86 Correct 455 ms 38872 KB Output is correct
87 Correct 479 ms 38996 KB Output is correct