oj.uz

Submission #849148

# Submission time Handle Problem Language Result Execution time Memory
849148 2023-09-14T07:18:40 Z sandry24 Network (BOI15_net) C++17
100 / 100
 362 ms 47716 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define pb push_back
#define mp make_pair
#define f first
#define s second

vector<vi> adj(500005);
vi leaves;

void dfs(int x, int p){
    bool has_children = 0;
    for(auto i : adj[x]){
        if(i != p){
            dfs(i, x);
            has_children = 1;
        }
    }
    if(!has_children)
        leaves.pb(x);
}
 
void solve(){
    int n;
    cin >> n;
    for(int i = 0; i < n-1; i++){
        int a, b;
        cin >> a >> b;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    if(adj[1].size() == 1)
        leaves.pb(1);
    dfs(1, -1);
    cout << ceil((double)leaves.size()/2) << '\n';
    for(int i = 0; i < leaves.size()/2; i++)
        cout << leaves[i] << ' ' << leaves[i + leaves.size()/2] << '\n';
    if(leaves.size() & 1)
        cout << leaves[0] << ' ' << leaves.back() << '\n';
}
 
int main(){
    //freopen("flota.in", "r", stdin);
    //freopen("flota.out", "w", stdout);
    ios::sync_with_stdio(0); cin.tie(0);
    int t = 1;
    //cin >> t;
    while(t--){
        solve();
    }
}

Compilation message

net.cpp: In function 'void solve()':
net.cpp:40:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |     for(int i = 0; i < leaves.size()/2; i++)
      |                    ~~^~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12120 KB Output is correct
2 Correct 3 ms 12120 KB Output is correct
3 Correct 3 ms 12124 KB Output is correct
4 Correct 3 ms 12120 KB Output is correct
5 Correct 3 ms 12124 KB Output is correct
6 Correct 3 ms 12124 KB Output is correct
7 Correct 4 ms 12124 KB Output is correct
8 Correct 3 ms 12124 KB Output is correct
9 Correct 3 ms 12124 KB Output is correct
10 Correct 3 ms 12124 KB Output is correct
11 Correct 3 ms 12124 KB Output is correct
12 Correct 3 ms 12120 KB Output is correct
13 Correct 3 ms 12124 KB Output is correct
14 Correct 3 ms 12124 KB Output is correct
15 Correct 3 ms 12132 KB Output is correct
16 Correct 4 ms 12124 KB Output is correct
17 Correct 3 ms 12124 KB Output is correct
18 Correct 3 ms 12124 KB Output is correct
19 Correct 4 ms 12124 KB Output is correct
20 Correct 3 ms 12124 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12120 KB Output is correct
2 Correct 3 ms 12120 KB Output is correct
3 Correct 3 ms 12124 KB Output is correct
4 Correct 3 ms 12120 KB Output is correct
5 Correct 3 ms 12124 KB Output is correct
6 Correct 3 ms 12124 KB Output is correct
7 Correct 4 ms 12124 KB Output is correct
8 Correct 3 ms 12124 KB Output is correct
9 Correct 3 ms 12124 KB Output is correct
10 Correct 3 ms 12124 KB Output is correct
11 Correct 3 ms 12124 KB Output is correct
12 Correct 3 ms 12120 KB Output is correct
13 Correct 3 ms 12124 KB Output is correct
14 Correct 3 ms 12124 KB Output is correct
15 Correct 3 ms 12132 KB Output is correct
16 Correct 4 ms 12124 KB Output is correct
17 Correct 3 ms 12124 KB Output is correct
18 Correct 3 ms 12124 KB Output is correct
19 Correct 4 ms 12124 KB Output is correct
20 Correct 3 ms 12124 KB Output is correct
21 Correct 3 ms 12376 KB Output is correct
22 Correct 4 ms 12124 KB Output is correct
23 Correct 4 ms 12124 KB Output is correct
24 Correct 4 ms 12124 KB Output is correct
25 Correct 3 ms 12224 KB Output is correct
26 Correct 3 ms 12124 KB Output is correct
27 Correct 5 ms 12120 KB Output is correct
28 Correct 3 ms 12224 KB Output is correct
29 Correct 3 ms 12124 KB Output is correct
30 Correct 3 ms 12200 KB Output is correct
31 Correct 3 ms 12124 KB Output is correct
32 Correct 3 ms 12124 KB Output is correct
33 Correct 3 ms 12320 KB Output is correct
34 Correct 4 ms 12124 KB Output is correct
35 Correct 3 ms 12120 KB Output is correct
36 Correct 4 ms 12124 KB Output is correct
37 Correct 3 ms 12120 KB Output is correct
38 Correct 4 ms 12124 KB Output is correct
39 Correct 4 ms 12124 KB Output is correct
40 Correct 3 ms 12124 KB Output is correct
41 Correct 3 ms 12124 KB Output is correct
42 Correct 3 ms 12124 KB Output is correct
43 Correct 4 ms 12212 KB Output is correct
44 Correct 4 ms 12124 KB Output is correct
45 Correct 4 ms 12120 KB Output is correct
46 Correct 3 ms 12224 KB Output is correct
47 Correct 3 ms 12124 KB Output is correct
48 Correct 4 ms 12124 KB Output is correct
49 Correct 4 ms 12124 KB Output is correct
50 Correct 4 ms 12124 KB Output is correct
51 Correct 3 ms 12124 KB Output is correct
52 Correct 4 ms 12124 KB Output is correct
53 Correct 3 ms 12124 KB Output is correct
54 Correct 4 ms 12124 KB Output is correct
55 Correct 4 ms 12124 KB Output is correct
56 Correct 3 ms 12124 KB Output is correct
57 Correct 3 ms 12124 KB Output is correct
58 Correct 3 ms 12124 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12120 KB Output is correct
2 Correct 3 ms 12120 KB Output is correct
3 Correct 3 ms 12124 KB Output is correct
4 Correct 3 ms 12120 KB Output is correct
5 Correct 3 ms 12124 KB Output is correct
6 Correct 3 ms 12124 KB Output is correct
7 Correct 4 ms 12124 KB Output is correct
8 Correct 3 ms 12124 KB Output is correct
9 Correct 3 ms 12124 KB Output is correct
10 Correct 3 ms 12124 KB Output is correct
11 Correct 3 ms 12124 KB Output is correct
12 Correct 3 ms 12120 KB Output is correct
13 Correct 3 ms 12124 KB Output is correct
14 Correct 3 ms 12124 KB Output is correct
15 Correct 3 ms 12132 KB Output is correct
16 Correct 4 ms 12124 KB Output is correct
17 Correct 3 ms 12124 KB Output is correct
18 Correct 3 ms 12124 KB Output is correct
19 Correct 4 ms 12124 KB Output is correct
20 Correct 3 ms 12124 KB Output is correct
21 Correct 3 ms 12376 KB Output is correct
22 Correct 4 ms 12124 KB Output is correct
23 Correct 4 ms 12124 KB Output is correct
24 Correct 4 ms 12124 KB Output is correct
25 Correct 3 ms 12224 KB Output is correct
26 Correct 3 ms 12124 KB Output is correct
27 Correct 5 ms 12120 KB Output is correct
28 Correct 3 ms 12224 KB Output is correct
29 Correct 3 ms 12124 KB Output is correct
30 Correct 3 ms 12200 KB Output is correct
31 Correct 3 ms 12124 KB Output is correct
32 Correct 3 ms 12124 KB Output is correct
33 Correct 3 ms 12320 KB Output is correct
34 Correct 4 ms 12124 KB Output is correct
35 Correct 3 ms 12120 KB Output is correct
36 Correct 4 ms 12124 KB Output is correct
37 Correct 3 ms 12120 KB Output is correct
38 Correct 4 ms 12124 KB Output is correct
39 Correct 4 ms 12124 KB Output is correct
40 Correct 3 ms 12124 KB Output is correct
41 Correct 3 ms 12124 KB Output is correct
42 Correct 3 ms 12124 KB Output is correct
43 Correct 4 ms 12212 KB Output is correct
44 Correct 4 ms 12124 KB Output is correct
45 Correct 4 ms 12120 KB Output is correct
46 Correct 3 ms 12224 KB Output is correct
47 Correct 3 ms 12124 KB Output is correct
48 Correct 4 ms 12124 KB Output is correct
49 Correct 4 ms 12124 KB Output is correct
50 Correct 4 ms 12124 KB Output is correct
51 Correct 3 ms 12124 KB Output is correct
52 Correct 4 ms 12124 KB Output is correct
53 Correct 3 ms 12124 KB Output is correct
54 Correct 4 ms 12124 KB Output is correct
55 Correct 4 ms 12124 KB Output is correct
56 Correct 3 ms 12124 KB Output is correct
57 Correct 3 ms 12124 KB Output is correct
58 Correct 3 ms 12124 KB Output is correct
59 Correct 202 ms 36148 KB Output is correct
60 Correct 255 ms 38860 KB Output is correct
61 Correct 3 ms 12120 KB Output is correct
62 Correct 3 ms 12124 KB Output is correct
63 Correct 181 ms 33600 KB Output is correct
64 Correct 4 ms 12636 KB Output is correct
65 Correct 10 ms 13916 KB Output is correct
66 Correct 99 ms 28008 KB Output is correct
67 Correct 357 ms 46884 KB Output is correct
68 Correct 362 ms 47716 KB Output is correct
69 Correct 8 ms 13012 KB Output is correct
70 Correct 47 ms 21284 KB Output is correct
71 Correct 192 ms 41944 KB Output is correct
72 Correct 203 ms 40772 KB Output is correct
73 Correct 42 ms 19152 KB Output is correct
74 Correct 282 ms 37772 KB Output is correct
75 Correct 16 ms 15324 KB Output is correct
76 Correct 211 ms 41624 KB Output is correct
77 Correct 162 ms 41644 KB Output is correct
78 Correct 19 ms 15452 KB Output is correct
79 Correct 334 ms 45140 KB Output is correct
80 Correct 5 ms 12380 KB Output is correct
81 Correct 68 ms 21220 KB Output is correct
82 Correct 253 ms 39476 KB Output is correct
83 Correct 253 ms 37576 KB Output is correct
84 Correct 243 ms 37832 KB Output is correct
85 Correct 318 ms 37596 KB Output is correct
86 Correct 292 ms 38668 KB Output is correct
87 Correct 294 ms 38800 KB Output is correct