Submission #386088

#	Time	Username	Problem	Language	Result	Execution time	Memory
386088		phathnv	Fun Tour (APIO20_fun)	C++11	0 / 100	36 ms	748 KiB

fun

#include <bits/stdc++.h>
#include "fun.h"

using namespace std;

vector<int> createFunTour(int N, int Q) {
    pair<int, int> best = {N, 0};
    for(int i = 0; i < N; i++){
        int x = attractionsBehind(0, i);
        cerr << i << ' ' << x << endl;
        if (x > N / 2)
            best = min(best, {x, i});
    }
    int centroid = best.second;
    cerr << "centroid: " << centroid << endl;

    vector<int> subtreeRoots, distToCentroid(N);
    for(int i = 0; i < N; i++){
        distToCentroid[i] = hoursRequired(centroid, i);
        if (distToCentroid[i] == 1)
            subtreeRoots.push_back(i);
    }
    vector<vector<pair<int, int>>> subtree(subtreeRoots.size());
    for(int i = 0; i < N; i++){
        if (i == centroid)
            continue;
        for(int j = 0; j < (int) subtreeRoots.size(); j++)
            if (j == (int) subtreeRoots.size())
                subtree[j].push_back({distToCentroid[i], i});
            else if (hoursRequired(subtreeRoots[j], i) == distToCentroid[i] - 1)
                subtree[j].push_back({distToCentroid[i], i});
    }
    for(auto &v : subtree)
        sort(v.begin(), v.end());
    for(auto v : subtree){
        for(auto p : v)
            cerr << p.first << ',' << p.second << ' ';
        cerr << endl;
    }

    vector<int> answer;
    int lastSubtree = -1;
    for(int i = 0; i < N - 1; i++){
        int rem = N - 1 - i;
        pair<int, int> best{-1, -1};
        for(int j = 0; j < (int) subtreeRoots.size(); j++){
            if (subtree[j].empty() || j == lastSubtree)
                continue;
            bool ok = 1;
            for(int k = 0; k < (int) subtreeRoots.size(); k++)
                ok &= ((int) subtree[k].size() * 2 <= rem + 1);
            if (ok)
                best = max(best, {subtree[j].back().first, j});
        }
        lastSubtree = best.second;
        cerr << "best: " << best.first << ' ' << best.second << endl;
        cerr << lastSubtree << ' ' << subtree[lastSubtree].back().second << endl;
        answer.push_back(subtree[lastSubtree].back().second);
        subtree[lastSubtree].pop_back();
    }
    answer.push_back(centroid);
    return answer;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 16
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 34