oj.uz

Submission #797485

# Submission time Handle Problem Language Result Execution time Memory
797485 2023-07-29T12:48:19 Z bonk Network (BOI15_net) C++14
100 / 100
 375 ms 56520 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 5e5 + 2;
vector<int>adj[N];
vector<pair<int, int>>t;
int timer = 0;

void dfs(int prev, int cur){
    timer++;
    bool leaf = true;
    for(auto &nxt: adj[cur]){
        if(prev == nxt) continue;
        leaf = false;
        dfs(cur, nxt);
    }

    if(leaf) t.emplace_back(timer, cur);
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int n; cin >> n;
    for(int i = 0; i < n - 1; i++){
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }


    for(int i = 1; i <= n; i++){
        if(adj[i].size() > 1){
            dfs(-1, i);
            break;
        }
    }

    sort(t.begin(), t.end());
    cout << (t.size() + 1)/2 << '\n';
    int half = t.size()/2;
    for(int i = 0; i < half; i++){
        cout << t[i].second << " " << t[i + half].second << '\n';
    }

    if(half*2 != t.size()){
        cout << t[0].second << " " << t.back().second << '\n';
    }

    return 0;
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:46:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |     if(half*2 != t.size()){
      |        ~~~~~~~^~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 12004 KB Output is correct
2 Correct 7 ms 11988 KB Output is correct
3 Correct 6 ms 11988 KB Output is correct
4 Correct 7 ms 11988 KB Output is correct
5 Correct 6 ms 12044 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 7 ms 12040 KB Output is correct
8 Correct 6 ms 12064 KB Output is correct
9 Correct 5 ms 11988 KB Output is correct
10 Correct 5 ms 12060 KB Output is correct
11 Correct 6 ms 12064 KB Output is correct
12 Correct 5 ms 11988 KB Output is correct
13 Correct 5 ms 11988 KB Output is correct
14 Correct 6 ms 12064 KB Output is correct
15 Correct 7 ms 11968 KB Output is correct
16 Correct 5 ms 12060 KB Output is correct
17 Correct 6 ms 12064 KB Output is correct
18 Correct 7 ms 11988 KB Output is correct
19 Correct 5 ms 11988 KB Output is correct
20 Correct 6 ms 12060 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 12004 KB Output is correct
2 Correct 7 ms 11988 KB Output is correct
3 Correct 6 ms 11988 KB Output is correct
4 Correct 7 ms 11988 KB Output is correct
5 Correct 6 ms 12044 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 7 ms 12040 KB Output is correct
8 Correct 6 ms 12064 KB Output is correct
9 Correct 5 ms 11988 KB Output is correct
10 Correct 5 ms 12060 KB Output is correct
11 Correct 6 ms 12064 KB Output is correct
12 Correct 5 ms 11988 KB Output is correct
13 Correct 5 ms 11988 KB Output is correct
14 Correct 6 ms 12064 KB Output is correct
15 Correct 7 ms 11968 KB Output is correct
16 Correct 5 ms 12060 KB Output is correct
17 Correct 6 ms 12064 KB Output is correct
18 Correct 7 ms 11988 KB Output is correct
19 Correct 5 ms 11988 KB Output is correct
20 Correct 6 ms 12060 KB Output is correct
21 Correct 5 ms 12008 KB Output is correct
22 Correct 6 ms 12116 KB Output is correct
23 Correct 6 ms 12072 KB Output is correct
24 Correct 7 ms 12112 KB Output is correct
25 Correct 8 ms 12132 KB Output is correct
26 Correct 5 ms 12068 KB Output is correct
27 Correct 8 ms 12120 KB Output is correct
28 Correct 5 ms 12116 KB Output is correct
29 Correct 6 ms 12116 KB Output is correct
30 Correct 5 ms 11988 KB Output is correct
31 Correct 8 ms 12116 KB Output is correct
32 Correct 6 ms 12072 KB Output is correct
33 Correct 5 ms 12056 KB Output is correct
34 Correct 6 ms 12064 KB Output is correct
35 Correct 5 ms 12064 KB Output is correct
36 Correct 7 ms 12044 KB Output is correct
37 Correct 8 ms 12064 KB Output is correct
38 Correct 6 ms 12116 KB Output is correct
39 Correct 6 ms 12060 KB Output is correct
40 Correct 5 ms 11988 KB Output is correct
41 Correct 6 ms 12068 KB Output is correct
42 Correct 5 ms 11988 KB Output is correct
43 Correct 5 ms 12064 KB Output is correct
44 Correct 5 ms 11988 KB Output is correct
45 Correct 6 ms 11988 KB Output is correct
46 Correct 6 ms 11988 KB Output is correct
47 Correct 5 ms 11988 KB Output is correct
48 Correct 5 ms 11988 KB Output is correct
49 Correct 7 ms 12116 KB Output is correct
50 Correct 5 ms 11988 KB Output is correct
51 Correct 5 ms 11988 KB Output is correct
52 Correct 6 ms 12064 KB Output is correct
53 Correct 6 ms 12072 KB Output is correct
54 Correct 6 ms 12068 KB Output is correct
55 Correct 6 ms 12064 KB Output is correct
56 Correct 6 ms 11988 KB Output is correct
57 Correct 6 ms 11984 KB Output is correct
58 Correct 6 ms 12156 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 12004 KB Output is correct
2 Correct 7 ms 11988 KB Output is correct
3 Correct 6 ms 11988 KB Output is correct
4 Correct 7 ms 11988 KB Output is correct
5 Correct 6 ms 12044 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 7 ms 12040 KB Output is correct
8 Correct 6 ms 12064 KB Output is correct
9 Correct 5 ms 11988 KB Output is correct
10 Correct 5 ms 12060 KB Output is correct
11 Correct 6 ms 12064 KB Output is correct
12 Correct 5 ms 11988 KB Output is correct
13 Correct 5 ms 11988 KB Output is correct
14 Correct 6 ms 12064 KB Output is correct
15 Correct 7 ms 11968 KB Output is correct
16 Correct 5 ms 12060 KB Output is correct
17 Correct 6 ms 12064 KB Output is correct
18 Correct 7 ms 11988 KB Output is correct
19 Correct 5 ms 11988 KB Output is correct
20 Correct 6 ms 12060 KB Output is correct
21 Correct 5 ms 12008 KB Output is correct
22 Correct 6 ms 12116 KB Output is correct
23 Correct 6 ms 12072 KB Output is correct
24 Correct 7 ms 12112 KB Output is correct
25 Correct 8 ms 12132 KB Output is correct
26 Correct 5 ms 12068 KB Output is correct
27 Correct 8 ms 12120 KB Output is correct
28 Correct 5 ms 12116 KB Output is correct
29 Correct 6 ms 12116 KB Output is correct
30 Correct 5 ms 11988 KB Output is correct
31 Correct 8 ms 12116 KB Output is correct
32 Correct 6 ms 12072 KB Output is correct
33 Correct 5 ms 12056 KB Output is correct
34 Correct 6 ms 12064 KB Output is correct
35 Correct 5 ms 12064 KB Output is correct
36 Correct 7 ms 12044 KB Output is correct
37 Correct 8 ms 12064 KB Output is correct
38 Correct 6 ms 12116 KB Output is correct
39 Correct 6 ms 12060 KB Output is correct
40 Correct 5 ms 11988 KB Output is correct
41 Correct 6 ms 12068 KB Output is correct
42 Correct 5 ms 11988 KB Output is correct
43 Correct 5 ms 12064 KB Output is correct
44 Correct 5 ms 11988 KB Output is correct
45 Correct 6 ms 11988 KB Output is correct
46 Correct 6 ms 11988 KB Output is correct
47 Correct 5 ms 11988 KB Output is correct
48 Correct 5 ms 11988 KB Output is correct
49 Correct 7 ms 12116 KB Output is correct
50 Correct 5 ms 11988 KB Output is correct
51 Correct 5 ms 11988 KB Output is correct
52 Correct 6 ms 12064 KB Output is correct
53 Correct 6 ms 12072 KB Output is correct
54 Correct 6 ms 12068 KB Output is correct
55 Correct 6 ms 12064 KB Output is correct
56 Correct 6 ms 11988 KB Output is correct
57 Correct 6 ms 11984 KB Output is correct
58 Correct 6 ms 12156 KB Output is correct
59 Correct 252 ms 37176 KB Output is correct
60 Correct 303 ms 40056 KB Output is correct
61 Correct 6 ms 12060 KB Output is correct
62 Correct 5 ms 11988 KB Output is correct
63 Correct 194 ms 34784 KB Output is correct
64 Correct 7 ms 12548 KB Output is correct
65 Correct 15 ms 14504 KB Output is correct
66 Correct 99 ms 33196 KB Output is correct
67 Correct 362 ms 55236 KB Output is correct
68 Correct 375 ms 56520 KB Output is correct
69 Correct 10 ms 13012 KB Output is correct
70 Correct 56 ms 21828 KB Output is correct
71 Correct 201 ms 43812 KB Output is correct
72 Correct 215 ms 42444 KB Output is correct
73 Correct 53 ms 19404 KB Output is correct
74 Correct 288 ms 38716 KB Output is correct
75 Correct 21 ms 15440 KB Output is correct
76 Correct 217 ms 43364 KB Output is correct
77 Correct 188 ms 43520 KB Output is correct
78 Correct 22 ms 16204 KB Output is correct
79 Correct 328 ms 52404 KB Output is correct
80 Correct 7 ms 12244 KB Output is correct
81 Correct 58 ms 21808 KB Output is correct
82 Correct 239 ms 40964 KB Output is correct
83 Correct 272 ms 38604 KB Output is correct
84 Correct 271 ms 38584 KB Output is correct
85 Correct 310 ms 38584 KB Output is correct
86 Correct 288 ms 40012 KB Output is correct
87 Correct 334 ms 40064 KB Output is correct