Submission #1065236

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065236		LittleOrange	Longest Trip (IOI23_longesttrip)	C++17	40 / 100	938 ms	852 KiB

longesttrip

#include "longesttrip.h"

#include <vector>
#include<bits/stdc++.h>
using namespace std;
using ll = int;

std::vector<int> longest_trip(int N, int D)
{
    mt19937_64 mt(random_device{}());
    ll n = N;
    if (D==3){
        vector<ll> r(n);
        iota(r.begin(),r.end(),0);
        return r;
    }
    vector<vector<ll>> a(n,vector<ll>(n,0));
    for(ll i = 0;i<n;i++){
        for(ll j = i+1;j<n;j++){
            a[i][j] = a[j][i] = are_connected({i},{j});
        }
    }
    vector<ll> ret;
    vector<ll> ord(n);
    iota(ord.begin(),ord.end(),0);
    vector<ll> cur;
    cur.reserve(n);
    ll cnt = 500000/max(n,10);
    while(cnt--){
        shuffle(ord.begin(),ord.end(),mt);
        cur.push_back(ord[0]);
        for(ll i : ord){
            if (a[cur.back()][i]) cur.push_back(i);
        }
        if(cur.size()>ret.size()) ret = cur;
        cur.clear();
    }
    return ret;
}

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 0 / 60