oj.uz

Submission #137097

# Submission time Handle Problem Language Result Execution time Memory
137097 2019-07-27T05:21:00 Z silxikys Network (BOI15_net) C++14
63 / 100
 2000 ms 55592 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
 
const int maxn = 5e5+5;
int n;
vector<int> adj[maxn];
int deg[maxn];
int tin[maxn];
int pt = 0;
 
void dfs(int i, int p) {
    tin[i] = pt++;
    for (int j: adj[i]) {
        if (j == p) continue;
        dfs(j,i);
    }
}
 
int main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    cin >> n;
    for (int i = 0; i < n - 1; i++) {
        int a, b; cin >> a >> b;
        ++deg[a];
        ++deg[b];
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    vector<int> leafs;
    int start = 1;
    for (int i = 1; i <= n; i++) {
        if (deg[i] == 1) leafs.push_back(i);
        if (deg[i] > 1) {
            start = i;
        }
    }
    for (int j: adj[start]) {
        dfs(j,j);
    }
    sort(leafs.begin(),leafs.end(),[](auto a, auto b) {
            return tin[a] < tin[b];
            });
    vector<pair<int,int>> ans;
    int k = leafs.size();
    int m = k/2;
    cout << (k+1)/2 << '\n';
    for (int i = 0; i < (k+1)/2; i++) {
        cout << leafs[i] << ' ' << leafs[(i+m)%k] << '\n';
    }
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 12020 KB Output is correct
2 Correct 15 ms 12152 KB Output is correct
3 Correct 12 ms 12028 KB Output is correct
4 Correct 13 ms 12024 KB Output is correct
5 Correct 12 ms 12152 KB Output is correct
6 Correct 12 ms 12024 KB Output is correct
7 Correct 12 ms 12152 KB Output is correct
8 Correct 13 ms 12152 KB Output is correct
9 Correct 12 ms 12024 KB Output is correct
10 Correct 12 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 12 ms 12024 KB Output is correct
13 Correct 12 ms 12024 KB Output is correct
14 Correct 15 ms 12124 KB Output is correct
15 Correct 12 ms 12024 KB Output is correct
16 Correct 12 ms 12024 KB Output is correct
17 Correct 12 ms 12024 KB Output is correct
18 Correct 13 ms 12072 KB Output is correct
19 Correct 13 ms 12024 KB Output is correct
20 Correct 16 ms 12024 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 12020 KB Output is correct
2 Correct 15 ms 12152 KB Output is correct
3 Correct 12 ms 12028 KB Output is correct
4 Correct 13 ms 12024 KB Output is correct
5 Correct 12 ms 12152 KB Output is correct
6 Correct 12 ms 12024 KB Output is correct
7 Correct 12 ms 12152 KB Output is correct
8 Correct 13 ms 12152 KB Output is correct
9 Correct 12 ms 12024 KB Output is correct
10 Correct 12 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 12 ms 12024 KB Output is correct
13 Correct 12 ms 12024 KB Output is correct
14 Correct 15 ms 12124 KB Output is correct
15 Correct 12 ms 12024 KB Output is correct
16 Correct 12 ms 12024 KB Output is correct
17 Correct 12 ms 12024 KB Output is correct
18 Correct 13 ms 12072 KB Output is correct
19 Correct 13 ms 12024 KB Output is correct
20 Correct 16 ms 12024 KB Output is correct
21 Correct 12 ms 12028 KB Output is correct
22 Correct 27 ms 12152 KB Output is correct
23 Correct 14 ms 12152 KB Output is correct
24 Correct 37 ms 12280 KB Output is correct
25 Correct 14 ms 12152 KB Output is correct
26 Correct 17 ms 12152 KB Output is correct
27 Correct 14 ms 12152 KB Output is correct
28 Correct 14 ms 12280 KB Output is correct
29 Correct 14 ms 12152 KB Output is correct
30 Correct 16 ms 12024 KB Output is correct
31 Correct 14 ms 12152 KB Output is correct
32 Correct 12 ms 12024 KB Output is correct
33 Correct 14 ms 12024 KB Output is correct
34 Correct 12 ms 12024 KB Output is correct
35 Correct 12 ms 12152 KB Output is correct
36 Correct 13 ms 12120 KB Output is correct
37 Correct 12 ms 12124 KB Output is correct
38 Correct 13 ms 12152 KB Output is correct
39 Correct 12 ms 12156 KB Output is correct
40 Correct 12 ms 12152 KB Output is correct
41 Correct 12 ms 12152 KB Output is correct
42 Correct 13 ms 12152 KB Output is correct
43 Correct 13 ms 12156 KB Output is correct
44 Correct 12 ms 12024 KB Output is correct
45 Correct 13 ms 12156 KB Output is correct
46 Correct 13 ms 12112 KB Output is correct
47 Correct 12 ms 12096 KB Output is correct
48 Correct 13 ms 12152 KB Output is correct
49 Correct 13 ms 12148 KB Output is correct
50 Correct 13 ms 12152 KB Output is correct
51 Correct 13 ms 12024 KB Output is correct
52 Correct 12 ms 12152 KB Output is correct
53 Correct 13 ms 12152 KB Output is correct
54 Correct 12 ms 12028 KB Output is correct
55 Correct 12 ms 12092 KB Output is correct
56 Correct 13 ms 12152 KB Output is correct
57 Correct 13 ms 12152 KB Output is correct
58 Correct 23 ms 12280 KB Output is correct

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 12020 KB Output is correct
2 Correct 15 ms 12152 KB Output is correct
3 Correct 12 ms 12028 KB Output is correct
4 Correct 13 ms 12024 KB Output is correct
5 Correct 12 ms 12152 KB Output is correct
6 Correct 12 ms 12024 KB Output is correct
7 Correct 12 ms 12152 KB Output is correct
8 Correct 13 ms 12152 KB Output is correct
9 Correct 12 ms 12024 KB Output is correct
10 Correct 12 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 12 ms 12024 KB Output is correct
13 Correct 12 ms 12024 KB Output is correct
14 Correct 15 ms 12124 KB Output is correct
15 Correct 12 ms 12024 KB Output is correct
16 Correct 12 ms 12024 KB Output is correct
17 Correct 12 ms 12024 KB Output is correct
18 Correct 13 ms 12072 KB Output is correct
19 Correct 13 ms 12024 KB Output is correct
20 Correct 16 ms 12024 KB Output is correct
21 Correct 12 ms 12028 KB Output is correct
22 Correct 27 ms 12152 KB Output is correct
23 Correct 14 ms 12152 KB Output is correct
24 Correct 37 ms 12280 KB Output is correct
25 Correct 14 ms 12152 KB Output is correct
26 Correct 17 ms 12152 KB Output is correct
27 Correct 14 ms 12152 KB Output is correct
28 Correct 14 ms 12280 KB Output is correct
29 Correct 14 ms 12152 KB Output is correct
30 Correct 16 ms 12024 KB Output is correct
31 Correct 14 ms 12152 KB Output is correct
32 Correct 12 ms 12024 KB Output is correct
33 Correct 14 ms 12024 KB Output is correct
34 Correct 12 ms 12024 KB Output is correct
35 Correct 12 ms 12152 KB Output is correct
36 Correct 13 ms 12120 KB Output is correct
37 Correct 12 ms 12124 KB Output is correct
38 Correct 13 ms 12152 KB Output is correct
39 Correct 12 ms 12156 KB Output is correct
40 Correct 12 ms 12152 KB Output is correct
41 Correct 12 ms 12152 KB Output is correct
42 Correct 13 ms 12152 KB Output is correct
43 Correct 13 ms 12156 KB Output is correct
44 Correct 12 ms 12024 KB Output is correct
45 Correct 13 ms 12156 KB Output is correct
46 Correct 13 ms 12112 KB Output is correct
47 Correct 12 ms 12096 KB Output is correct
48 Correct 13 ms 12152 KB Output is correct
49 Correct 13 ms 12148 KB Output is correct
50 Correct 13 ms 12152 KB Output is correct
51 Correct 13 ms 12024 KB Output is correct
52 Correct 12 ms 12152 KB Output is correct
53 Correct 13 ms 12152 KB Output is correct
54 Correct 12 ms 12028 KB Output is correct
55 Correct 12 ms 12092 KB Output is correct
56 Correct 13 ms 12152 KB Output is correct
57 Correct 13 ms 12152 KB Output is correct
58 Correct 23 ms 12280 KB Output is correct
59 Correct 545 ms 34124 KB Output is correct
60 Correct 703 ms 36648 KB Output is correct
61 Correct 13 ms 12024 KB Output is correct
62 Correct 13 ms 12024 KB Output is correct
63 Correct 500 ms 31900 KB Output is correct
64 Correct 16 ms 12536 KB Output is correct
65 Correct 27 ms 13944 KB Output is correct
66 Correct 226 ms 24772 KB Output is correct
67 Correct 715 ms 55592 KB Output is correct
68 Correct 829 ms 48588 KB Output is correct
69 Correct 21 ms 13048 KB Output is correct
70 Correct 137 ms 20908 KB Output is correct
71 Execution timed out 2047 ms 36192 KB Time limit exceeded
72 Halted 0 ms 0 KB -