Submission #1076213

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076213		MarwenElarbi	Longest Trip (IOI23_longesttrip)	C++17	5 / 100	882 ms	968 KiB

longesttrip

#include <bits/stdc++.h>
#include "longesttrip.h"
using namespace std;
#define pb push_back
#define fi first
#define se second
const int nax = 2e5+5;
const int MOD = 1e9+7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
vector<int> adj[256];
bool vis[256];
set<int> components[256];
void dfs(int x,int p){
    components[p].insert(x);
    vis[x]=true;
    for(auto u:adj[x]){
        if(vis[u]) continue;
        dfs(u,p);
    }return;
}
std::vector<int> longest_trip(int N, int D)
{
    vector<int> a,b;
    for (int i = 0; i < N; ++i)
    {
        vis[i]=0;
        adj[i].clear();
        components[i].clear();
    }
    for (int i = 0; i < N; ++i)
    {
        for (int j = i+1; j < N; ++j)
        {
            if(are_connected({i},{j})){
                adj[i].pb(j);
                adj[j].pb(i);
            }else{
                a.pb(i);
                b.pb(j);
            }
        }
    }
    pair<int,int> big={-1,-1};
    int cnt=0;
    for (int i = 0; i < N; ++i)
    {
        if(vis[i]) continue;
        cnt++;
        dfs(i,i);
        if(big.fi<(int)components[i].size()){
            big={(int)components[i].size(),i};
        }
    }
    vector<int> ans;
    shuffle(a.begin(),a.end(),rng);
    shuffle(b.begin(),b.end(),rng);
    if(a.size()==0){
        for (int i = 0; i < N; ++i)
        {
            ans.pb(i);
        }
    }else if(cnt>1){
        for(auto u:components[big.se]){
            ans.pb(u);
        }
    }else{
        memset(vis,0,sizeof vis);
        for(auto u:a){
            if(components[big.se].count(u)) {
                ans.pb(u);
                vis[u]=true;
            }
        }
        for(auto u:components[big.se]){
            if(!vis[u]) ans.pb(u);
        }
        for(auto u:b){
            if(components[big.se].count(u)){
                ans.pb(u);
                vis[u]=true;
            }
        }
        
    }
    
    return ans;
}

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