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Submission #169006

# Submission time Handle Problem Language Result Execution time Memory
169006 2019-12-17T13:57:37 Z _qVp_ Network (BOI15_net) C++14
0 / 100
 23 ms 23800 KB 
#include <bits/stdc++.h>

using namespace std;

const int md = 1e6 + 10;

vector < int > adj[md];
vector < int > leaves;
int n;

void dfs(int u, int par) {
    if (adj[u].size() == 1)
        leaves.push_back(u);
    for(auto v : adj[u]) {
        if (v != par)
            dfs(v, u);
    }
}

int main() {
    //freopen("test.in", "r", stdin);
    ios_base::sync_with_stdio(0);
    cin >> n;
    for(int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    leaves.push_back(0);
    dfs(1, -1);
    int len = leaves.size() - 1;
    cout << (len + 1) / 2 << '\n';
    for(int i = 1; i <= len / 2; i++) 
        cout << leaves[i] << " " << leaves[len - i + 1] << '\n';
    if (len & 1)
        cout << leaves[len / 2] << " " << leaves[len / 2 + 1];
    return 0;
}

Subtask #1
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 23800 KB Output is correct
2 Incorrect 23 ms 23800 KB Breaking single line is causing network to disconnect.
3 Halted 0 ms 0 KB -

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 23800 KB Output is correct
2 Incorrect 23 ms 23800 KB Breaking single line is causing network to disconnect.
3 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 23800 KB Output is correct
2 Incorrect 23 ms 23800 KB Breaking single line is causing network to disconnect.
3 Halted 0 ms 0 KB -