Submission #836301

#	Time	Username	Problem	Language	Result	Execution time	Memory
836301		ALeonidou	Thousands Islands (IOI22_islands)	C++17	6.75 / 100	27 ms	4656 KiB

islands

#include "islands.h"

#include <variant>
#include <bits/stdc++.h>

using namespace std;
#define ll int
#define sz(x) (ll)x.size()
#define F first
#define S second
#define MID ((l+r)/2)
#define pb push_back
#define dbg(x) cout<<#x<<": "<<x<<endl;
#define dbg2(x,y) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<endl;
#define dbg3(x,y,z) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<" "<<#z<<": "<<z<<endl;
#define dbg4(x,y,z,w) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<" "<<#z<<": "<<z<<" "<<#w<<": "<<w<<endl;
#define dbg5(x,y,z,w,q) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<" "<<#z<<": "<<z<<" "<<#w<<": "<<w<<" "<<#q<<": "<<q<<endl;


typedef vector <ll> vi;
typedef pair <ll,ll> ii;
typedef vector <ii> vii;
#define MOD 1000002022
#define inf 1e9

vector <vi> adj;

vi vis;
bool dfs(ll u, ll p){
    if (u == 0) return true;
    vis[u] = 1;
    for (ll i=0; i<sz(adj[u]); i++){
        if (adj[u][i] != p && !vis[adj[u][i]]){
            if (dfs(adj[u][i], u)) return true;
        }
    }
    return false;
}

variant<bool, vi> find_journey(int N, int M, vi U, vi V){
    ll n = N, m = M;
    vi a, b;


    if (n == 2){
        for (ll i =0; i<m; i++){
            if (U[i] == 0) a.pb(i);
            else b.pb(i);
        }

        bool ok =  (sz(a) >= 2 && sz(b) >= 1);
        
        vi v(6);
        if (ok){
            vi v(6);
            ll x = a[0], y = b[0], z = a[1];
            v[0] = x, v[1] = y, v[2] = z;
            v[3] = x, v[4] = y, v[5] = z;
            return v;
        }
        return false;
    }
    else{
        //SUBTASK 3
        adj.assign(n, vi());
        for (ll i=0; i<m;i++){
            adj[U[i]].pb(V[i]);
        }

        vis.assign(n, 0);
        bool ok = false;
        for (ll i=0; i<sz(adj[0]); i++){
            ok = dfs(adj[0][i], 0);
            if (ok) break;
        }

        if (ok) return vi();
        else return false;
    }

}

• Subtask 1: 5 / 5
• Subtask 2: 1.75 / 5
• Subtask 3: 0 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 45