oj.uz

Submission #98253

# Submission time Handle Problem Language Result Execution time Memory
98253 2019-02-21T17:13:43 Z win11905 Network (BOI15_net) C++11
100 / 100
 814 ms 53116 KB 
/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author win11905
 */

#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define vi vector<int>
#define iii tuple<int, int, int>
#define long long long
#define pii pair<int, int>
#define x first
#define y second
using namespace std;
const long MOD = 1e9+7, LINF = 1e18 + 1e16;
const int INF = 1e9+1;
const double EPS = 1e-10;
const int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};

const int N = 5e5+5;

class net {
private:
    int n;
    vector<int> g[N], ans;
    void dfs(int u, int p) {
        if(g[u].size() == 1) ans.emplace_back(u);
        for(int v : g[u]) if(v != p) dfs(v, u);
    }
public:
    void solve(istream& cin, ostream& cout) {
        cin >> n;
        int snode;
        for(int i = 1, u, v; i < n; ++i) {
            cin >> u >> v;
            g[u].emplace_back(v), g[v].emplace_back(u);

        }
        for(int i = 1; i <= n; ++i) if(g[i].size() > 1) snode = i;
        dfs(snode, 0);
        int m = ((int)ans.size() + 1) >> 1;
        cout << m << endl;
        if(ans.size() % 2) cout << snode << ' ' << ans[m-1] << endl;
        for(int i = 0; i+m < (int)ans.size(); ++i) cout << ans[i] << ' ' << ans[i+m] << endl;
    }
};

class Solver {
public:
    void solve(std::istream& in, std::ostream& out) {
        net *obj = new net();
        obj->solve(in, out);
    }
};

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    Solver solver;
    std::istream& in(std::cin);
    std::ostream& out(std::cout);
    solver.solve(in, out);
    return 0;
}

Compilation message

net.cpp: In member function 'void net::solve(std::istream&, std::ostream&)':
net.cpp:34:13: warning: 'snode' may be used uninitialized in this function [-Wmaybe-uninitialized]
         int snode;
             ^~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 12160 KB Output is correct
2 Correct 15 ms 12160 KB Output is correct
3 Correct 14 ms 12032 KB Output is correct
4 Correct 15 ms 12160 KB Output is correct
5 Correct 14 ms 12160 KB Output is correct
6 Correct 17 ms 12160 KB Output is correct
7 Correct 14 ms 12032 KB Output is correct
8 Correct 15 ms 12160 KB Output is correct
9 Correct 14 ms 12032 KB Output is correct
10 Correct 15 ms 12172 KB Output is correct
11 Correct 15 ms 12160 KB Output is correct
12 Correct 15 ms 12160 KB Output is correct
13 Correct 15 ms 12160 KB Output is correct
14 Correct 16 ms 12160 KB Output is correct
15 Correct 15 ms 12160 KB Output is correct
16 Correct 16 ms 12160 KB Output is correct
17 Correct 14 ms 12032 KB Output is correct
18 Correct 17 ms 12032 KB Output is correct
19 Correct 14 ms 12032 KB Output is correct
20 Correct 14 ms 12032 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 12160 KB Output is correct
2 Correct 15 ms 12160 KB Output is correct
3 Correct 14 ms 12032 KB Output is correct
4 Correct 15 ms 12160 KB Output is correct
5 Correct 14 ms 12160 KB Output is correct
6 Correct 17 ms 12160 KB Output is correct
7 Correct 14 ms 12032 KB Output is correct
8 Correct 15 ms 12160 KB Output is correct
9 Correct 14 ms 12032 KB Output is correct
10 Correct 15 ms 12172 KB Output is correct
11 Correct 15 ms 12160 KB Output is correct
12 Correct 15 ms 12160 KB Output is correct
13 Correct 15 ms 12160 KB Output is correct
14 Correct 16 ms 12160 KB Output is correct
15 Correct 15 ms 12160 KB Output is correct
16 Correct 16 ms 12160 KB Output is correct
17 Correct 14 ms 12032 KB Output is correct
18 Correct 17 ms 12032 KB Output is correct
19 Correct 14 ms 12032 KB Output is correct
20 Correct 14 ms 12032 KB Output is correct
21 Correct 15 ms 12160 KB Output is correct
22 Correct 18 ms 12288 KB Output is correct
23 Correct 18 ms 12152 KB Output is correct
24 Correct 18 ms 12288 KB Output is correct
25 Correct 17 ms 12288 KB Output is correct
26 Correct 15 ms 12160 KB Output is correct
27 Correct 16 ms 12160 KB Output is correct
28 Correct 16 ms 12288 KB Output is correct
29 Correct 15 ms 12160 KB Output is correct
30 Correct 15 ms 12032 KB Output is correct
31 Correct 18 ms 12160 KB Output is correct
32 Correct 14 ms 12040 KB Output is correct
33 Correct 14 ms 12160 KB Output is correct
34 Correct 17 ms 12160 KB Output is correct
35 Correct 13 ms 12032 KB Output is correct
36 Correct 14 ms 12160 KB Output is correct
37 Correct 14 ms 12160 KB Output is correct
38 Correct 15 ms 12152 KB Output is correct
39 Correct 15 ms 12032 KB Output is correct
40 Correct 15 ms 12032 KB Output is correct
41 Correct 14 ms 12032 KB Output is correct
42 Correct 15 ms 12160 KB Output is correct
43 Correct 15 ms 12160 KB Output is correct
44 Correct 15 ms 12032 KB Output is correct
45 Correct 16 ms 12160 KB Output is correct
46 Correct 15 ms 12160 KB Output is correct
47 Correct 15 ms 12032 KB Output is correct
48 Correct 15 ms 12160 KB Output is correct
49 Correct 16 ms 12160 KB Output is correct
50 Correct 14 ms 12032 KB Output is correct
51 Correct 16 ms 12160 KB Output is correct
52 Correct 14 ms 12160 KB Output is correct
53 Correct 16 ms 12160 KB Output is correct
54 Correct 14 ms 12032 KB Output is correct
55 Correct 17 ms 12160 KB Output is correct
56 Correct 13 ms 12160 KB Output is correct
57 Correct 17 ms 12160 KB Output is correct
58 Correct 17 ms 12160 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 12160 KB Output is correct
2 Correct 15 ms 12160 KB Output is correct
3 Correct 14 ms 12032 KB Output is correct
4 Correct 15 ms 12160 KB Output is correct
5 Correct 14 ms 12160 KB Output is correct
6 Correct 17 ms 12160 KB Output is correct
7 Correct 14 ms 12032 KB Output is correct
8 Correct 15 ms 12160 KB Output is correct
9 Correct 14 ms 12032 KB Output is correct
10 Correct 15 ms 12172 KB Output is correct
11 Correct 15 ms 12160 KB Output is correct
12 Correct 15 ms 12160 KB Output is correct
13 Correct 15 ms 12160 KB Output is correct
14 Correct 16 ms 12160 KB Output is correct
15 Correct 15 ms 12160 KB Output is correct
16 Correct 16 ms 12160 KB Output is correct
17 Correct 14 ms 12032 KB Output is correct
18 Correct 17 ms 12032 KB Output is correct
19 Correct 14 ms 12032 KB Output is correct
20 Correct 14 ms 12032 KB Output is correct
21 Correct 15 ms 12160 KB Output is correct
22 Correct 18 ms 12288 KB Output is correct
23 Correct 18 ms 12152 KB Output is correct
24 Correct 18 ms 12288 KB Output is correct
25 Correct 17 ms 12288 KB Output is correct
26 Correct 15 ms 12160 KB Output is correct
27 Correct 16 ms 12160 KB Output is correct
28 Correct 16 ms 12288 KB Output is correct
29 Correct 15 ms 12160 KB Output is correct
30 Correct 15 ms 12032 KB Output is correct
31 Correct 18 ms 12160 KB Output is correct
32 Correct 14 ms 12040 KB Output is correct
33 Correct 14 ms 12160 KB Output is correct
34 Correct 17 ms 12160 KB Output is correct
35 Correct 13 ms 12032 KB Output is correct
36 Correct 14 ms 12160 KB Output is correct
37 Correct 14 ms 12160 KB Output is correct
38 Correct 15 ms 12152 KB Output is correct
39 Correct 15 ms 12032 KB Output is correct
40 Correct 15 ms 12032 KB Output is correct
41 Correct 14 ms 12032 KB Output is correct
42 Correct 15 ms 12160 KB Output is correct
43 Correct 15 ms 12160 KB Output is correct
44 Correct 15 ms 12032 KB Output is correct
45 Correct 16 ms 12160 KB Output is correct
46 Correct 15 ms 12160 KB Output is correct
47 Correct 15 ms 12032 KB Output is correct
48 Correct 15 ms 12160 KB Output is correct
49 Correct 16 ms 12160 KB Output is correct
50 Correct 14 ms 12032 KB Output is correct
51 Correct 16 ms 12160 KB Output is correct
52 Correct 14 ms 12160 KB Output is correct
53 Correct 16 ms 12160 KB Output is correct
54 Correct 14 ms 12032 KB Output is correct
55 Correct 17 ms 12160 KB Output is correct
56 Correct 13 ms 12160 KB Output is correct
57 Correct 17 ms 12160 KB Output is correct
58 Correct 17 ms 12160 KB Output is correct
59 Correct 703 ms 36184 KB Output is correct
60 Correct 814 ms 38872 KB Output is correct
61 Correct 15 ms 12160 KB Output is correct
62 Correct 13 ms 12032 KB Output is correct
63 Correct 586 ms 33648 KB Output is correct
64 Correct 16 ms 12280 KB Output is correct
65 Correct 26 ms 13696 KB Output is correct
66 Correct 200 ms 24248 KB Output is correct
67 Correct 637 ms 53116 KB Output is correct
68 Correct 664 ms 47856 KB Output is correct
69 Correct 33 ms 13048 KB Output is correct
70 Correct 255 ms 21228 KB Output is correct
71 Correct 721 ms 41944 KB Output is correct
72 Correct 614 ms 40676 KB Output is correct
73 Correct 205 ms 19060 KB Output is correct
74 Correct 693 ms 37768 KB Output is correct
75 Correct 72 ms 15352 KB Output is correct
76 Correct 674 ms 41692 KB Output is correct
77 Correct 685 ms 41696 KB Output is correct
78 Correct 68 ms 15224 KB Output is correct
79 Correct 579 ms 42968 KB Output is correct
80 Correct 20 ms 12408 KB Output is correct
81 Correct 226 ms 21584 KB Output is correct
82 Correct 675 ms 39568 KB Output is correct
83 Correct 721 ms 37740 KB Output is correct
84 Correct 696 ms 37696 KB Output is correct
85 Correct 673 ms 37716 KB Output is correct
86 Correct 742 ms 38920 KB Output is correct
87 Correct 771 ms 38896 KB Output is correct