Submission #1079597

#	Time	Username	Problem	Language	Result	Execution time	Memory
1079597		Lalic	Thousands Islands (IOI22_islands)	C++17	30.75 / 100	33 ms	6140 KiB

islands

#include "islands.h"
//~ #include <variant>
#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define allr(x) x.rbegin(), x.rend()
#define mp make_pair

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef complex<double> cd;

bool calc(int ver, int prev, vector<vector<pii>>& adj, vector<int>& cam, vector<int>& path, vector<int>& viz){
	viz[ver]=1;
	path.pb(ver);
	
	for(int i=0;i<(int)adj[ver].size();i+=2){
		pii u=adj[ver][i];
		
		if(viz[u.fi]==2) continue;
		
		if(viz[u.fi]==0){
			cam.pb(u.se);
			if(calc(u.fi, ver, adj, cam, path, viz)) return 1;
			cam.pop_back();
		}
		else{
			cam.pb(u.se);
			int ptrcam=(int)cam.size()-2, ptrpath=(int)path.size()-1;
			
			vector<int> rep={u.se};
			do{
				rep.pb(cam[ptrcam--]);
				ptrpath--;
			}while(path[ptrpath]!=u.fi);
			
			vector<int> aux=cam;
			reverse(all(aux));
			
			reverse(all(rep));
			
			for(auto at : rep) cam.pb(at+1);
			
			reverse(all(rep));
			
			for(auto at : rep) cam.pb(at);
			for(auto at : rep) cam.pb(at+1);
			
			for(int j=(int)rep.size();j<(int)aux.size();j++) cam.pb(aux[j]);
			
			return 1;
		}
	}
	
	path.pop_back();
	viz[ver]=2;
	
	return 0;
}

variant<bool, vector<int>> find_journey(int N, int M, vector<int> U, vector<int> V) {
	vector<vector<pii>> adj(N);
	
	for(int i=0;i<M;i++) 
		adj[U[i]].pb({V[i], i});
	
	if(N==2){
		if((int)adj[0].size()>=2 && adj[1].size()>=1){
			int a=adj[0][0].se, b=adj[0][1].se, c=adj[1][0].se;
			return vector<int>({a, c, b, a, c, b});
		}
		return false;
	}
	
	vector<int> ans, aux, viz(N, 0);
	if(calc(0, -1, adj, ans, aux, viz)) return ans;
	return false;
}

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