Submission #1024517

#	Time	Username	Problem	Language	Result	Execution time	Memory
1024517		stdfloat	Torrent (COI16_torrent)	C++17	0 / 100	2061 ms	20316 KiB

torrent

#include <bits/stdc++.h>
using namespace std;

using ll = long long;

vector<bool> vis;

vector<vector<int>> E;

int dfs(int x) {
    vis[x] = true;

    vector<int> v;
    for (auto i : E[x]) {
        if (!vis[i]) v.push_back(dfs(i));
    }

    sort(v.rbegin(), v.rend());

    int mx = 0;
    for (int i = 0; i < (int)v.size(); i++) mx = max(mx, v[i] + i + 1);

    return mx;
}

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);

    int n, a, b;
    cin >> n >> a >> b; a--; b--;

    E.assign(n, {});
    for (int i = 1; i < n; i++) {
        int x, y;
        cin >> x >> y;
        
        E[--x].push_back(--y);
        E[y].push_back(x);
    }

    int mn = INT_MAX;
    for (int i = 0; i < n; i++) {
        if (i == b) continue;
    
        vis.assign(n, false);
        vis[a] = vis[b] = vis[i] = true;
    
        int y = dfs(b);
        vis[i] = false;
        int x = dfs(a);

        mn = min(mn, max(x, y));
    }

    cout << mn;
}

• Subtask 1: 0 / 31
• Subtask 2: 0 / 69