Submission #471696

#	Time	Username	Problem	Language	Result	Execution time	Memory
471696		Rainbowbunny	Meetings (JOI19_meetings)	C++17	100 / 100	853 ms	1084 KiB

meetings

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

static int tmp;

const int MAXN = 2005;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int random(int l, int r)
{
    return rng() % (r - l + 1) + l;
}

vector <int> Com[MAXN];

void DFS(vector <int> V)
{
    if((int)V.size() < 2)
    {
        return;
    }
    if((int)V.size() == 2)
    {
        Bridge(min(V[0], V[1]), max(V[0], V[1]));
        return;
    }
    int root = V[0], ran = V[random(1, (int)V.size() - 1)];
    for(auto x : V)
    {
        Com[x].clear();
    }
    for(auto x : V)
    {
        if(x != root and x != ran)
        {
            Com[Query(root, ran, x)].push_back(x);
        }
    }
    vector <int> Path;
    for(auto x : V)
    {
        if(!Com[x].empty() and x != root and x != ran)
        {
            Path.push_back(x);
        }
    }
    tmp = root;
    sort(Path.begin(), Path.end(), [](int x, int y)
    {
        return Query(tmp, x, y) == x;
    });
    if(!Path.empty())
    {
        Bridge(min(root, Path[0]), max(root, Path[0]));
        Bridge(min(Path.back(), ran), max(Path.back(), ran));
    }
    else
    {
        Bridge(min(root, ran), max(root, ran));
    }
    for(int i = 0; i < (int)Path.size(); i++)
    {
        if(i + 1 < (int)Path.size())
        {
            Bridge(min(Path[i], Path[i + 1]), max(Path[i], Path[i + 1]));
        }
        DFS(Com[Path[i]]);
    }
    Com[root].push_back(root);
    Com[ran].push_back(ran);
    DFS(Com[root]);
    DFS(Com[ran]);
}

void Solve(int N)
{
    vector <int> V;
    for(int i = 0; i < N; i++)
    {
        V.push_back(i);
    }
    DFS(V);
}

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 12 / 12
• Subtask 4: 71 / 71