Submission #304916

#	Time	Username	Problem	Language	Result	Execution time	Memory
304916		kevinsogo	Stations (IOI20_stations)	C++17	100 / 100	1394 ms	1088 KiB

stations

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

struct Labeller {
    int n, ord = 0;
    vector<vector<int>> adj;
    vector<int> labels;
    Labeller(int n, const vector<int>& u, const vector<int>& v): n(n), adj(n), labels(n) {
        for (int i = 0; i < n - 1; i++) {
            adj[u[i]].push_back(v[i]);
            adj[v[i]].push_back(u[i]);
        }
        preposterous(0, -1, false);
        assert(ord == n);
    }

    void preposterous(int s, int p, bool x) {
        if (x) labels[s] = ord++;
        for (int t : adj[s]) if (t != p) preposterous(t, s, !x);
        if (!x) labels[s] = ord++;
    }
};

vector<int> label(int n, int k, vector<int> u, vector<int> v) {
    return Labeller(n, u, v).labels;
}

int find_next_station(int s, int t, vector<int> c) {
    if (s > c.back()) reverse(c.begin(), c.end());
    for (int u : c) if (min(u, s) <= t && t <= max(u, s)) return u;
    return c.back();
}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61