oj.uz

Submission #922724

# Submission time Handle Problem Language Result Execution time Memory
922724 2024-02-06T04:18:54 Z Alihan_8 Network (BOI15_net) C++17
100 / 100
 417 ms 39948 KB 
#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
#define int long long

using i64 = long long;

template <class F, class _S>
bool chmin(F &u, const _S &v){
    bool flag = false;
    if ( u > v ){
        u = v; flag |= true;
    }
    return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
    bool flag = false;
    if ( u < v ){
        u = v; flag |= true;
    }
    return flag;
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n; cin >> n;

    vector <vector<int>> G(n);

    for ( int i = 1; i < n; i++ ){
        int u, v; cin >> u >> v;
        --u, --v;
        G[u].pb(v), G[v].pb(u);
    }

    vector <int> lf;

    auto dfs = [&](auto dfs, int u, int p) -> void{
        if ( G[u].size() == 1 ){
            lf.pb(u);
        }
        for ( auto &v: G[u] ){
            if ( v != p ){
                dfs(dfs, v, u);
            }
        }
    };

    dfs(dfs, 0, -1);

    if ( lf.size() & 1 ){
        lf.pb(lf[0]);
    }

    int k = lf.size();
    cout << k / 2 << ln;
    for ( int i = 0; i * 2 < k; i++ ){
        cout << lf[i] + 1 << ' ' << lf[i + k / 2] + 1 << ln;
    }

    cout << '\n';
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 344 KB Output is correct
20 Correct 0 ms 348 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 344 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 600 KB Output is correct
23 Correct 1 ms 604 KB Output is correct
24 Correct 1 ms 604 KB Output is correct
25 Correct 1 ms 604 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 1 ms 604 KB Output is correct
28 Correct 1 ms 604 KB Output is correct
29 Correct 1 ms 348 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 1 ms 376 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 1 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 1 ms 344 KB Output is correct
36 Correct 1 ms 348 KB Output is correct
37 Correct 1 ms 348 KB Output is correct
38 Correct 1 ms 344 KB Output is correct
39 Correct 1 ms 344 KB Output is correct
40 Correct 0 ms 348 KB Output is correct
41 Correct 1 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 0 ms 348 KB Output is correct
44 Correct 0 ms 344 KB Output is correct
45 Correct 1 ms 344 KB Output is correct
46 Correct 1 ms 348 KB Output is correct
47 Correct 1 ms 344 KB Output is correct
48 Correct 1 ms 348 KB Output is correct
49 Correct 1 ms 348 KB Output is correct
50 Correct 0 ms 344 KB Output is correct
51 Correct 0 ms 348 KB Output is correct
52 Correct 0 ms 348 KB Output is correct
53 Correct 1 ms 348 KB Output is correct
54 Correct 0 ms 344 KB Output is correct
55 Correct 1 ms 348 KB Output is correct
56 Correct 0 ms 348 KB Output is correct
57 Correct 1 ms 344 KB Output is correct
58 Correct 1 ms 604 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 344 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 600 KB Output is correct
23 Correct 1 ms 604 KB Output is correct
24 Correct 1 ms 604 KB Output is correct
25 Correct 1 ms 604 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 1 ms 604 KB Output is correct
28 Correct 1 ms 604 KB Output is correct
29 Correct 1 ms 348 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 1 ms 376 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 1 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 1 ms 344 KB Output is correct
36 Correct 1 ms 348 KB Output is correct
37 Correct 1 ms 348 KB Output is correct
38 Correct 1 ms 344 KB Output is correct
39 Correct 1 ms 344 KB Output is correct
40 Correct 0 ms 348 KB Output is correct
41 Correct 1 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 0 ms 348 KB Output is correct
44 Correct 0 ms 344 KB Output is correct
45 Correct 1 ms 344 KB Output is correct
46 Correct 1 ms 348 KB Output is correct
47 Correct 1 ms 344 KB Output is correct
48 Correct 1 ms 348 KB Output is correct
49 Correct 1 ms 348 KB Output is correct
50 Correct 0 ms 344 KB Output is correct
51 Correct 0 ms 348 KB Output is correct
52 Correct 0 ms 348 KB Output is correct
53 Correct 1 ms 348 KB Output is correct
54 Correct 0 ms 344 KB Output is correct
55 Correct 1 ms 348 KB Output is correct
56 Correct 0 ms 348 KB Output is correct
57 Correct 1 ms 344 KB Output is correct
58 Correct 1 ms 604 KB Output is correct
59 Correct 285 ms 34904 KB Output is correct
60 Correct 362 ms 36800 KB Output is correct
61 Correct 0 ms 344 KB Output is correct
62 Correct 1 ms 348 KB Output is correct
63 Correct 288 ms 30680 KB Output is correct
64 Correct 2 ms 856 KB Output is correct
65 Correct 8 ms 2396 KB Output is correct
66 Correct 95 ms 17072 KB Output is correct
67 Correct 382 ms 38400 KB Output is correct
68 Correct 417 ms 39948 KB Output is correct
69 Correct 6 ms 1628 KB Output is correct
70 Correct 55 ms 13384 KB Output is correct
71 Correct 185 ms 39352 KB Output is correct
72 Correct 215 ms 38468 KB Output is correct
73 Correct 54 ms 9928 KB Output is correct
74 Correct 314 ms 34496 KB Output is correct
75 Correct 14 ms 4564 KB Output is correct
76 Correct 226 ms 38572 KB Output is correct
77 Correct 190 ms 39336 KB Output is correct
78 Correct 16 ms 4444 KB Output is correct
79 Correct 358 ms 37244 KB Output is correct
80 Correct 1 ms 600 KB Output is correct
81 Correct 64 ms 12816 KB Output is correct
82 Correct 298 ms 36744 KB Output is correct
83 Correct 299 ms 34500 KB Output is correct
84 Correct 336 ms 34568 KB Output is correct
85 Correct 314 ms 34688 KB Output is correct
86 Correct 312 ms 38336 KB Output is correct
87 Correct 320 ms 36800 KB Output is correct