Submission #1235686

#	Time	Username	Problem	Language	Result	Execution time	Memory
1235686		MuhammadSaram	Thousands Islands (IOI22_islands)	C++20	0 / 100	1098 ms	135720 KiB

islands

#include "islands.h"
#include <bits/stdc++.h>

using namespace std;

const int M = 1000;

vector<int> nei[M],ans;
map<pair<int,int>,int> ind; 
int vis[M], par[M];

void dfs(int u)
{
	vis[u]=1;
	if (ans.size()) return;
	for (int i:nei[u])
		if (!vis[i])
			par[i]=u,dfs(i);
		else if(vis[i]==1)
		{
			int v=u;
			while (v)
				ans.push_back(ind[{par[v],v}]),v=par[v];
			reverse(ans.begin(),ans.end());
			ans.push_back(ind[{u,i}]);
			int m=ans.size();
			for (int o=0;o<m;o++)
			{
				if (ans[o]==ind[{par[i],i}])
				{
					for (int j=o+1;j<m;j++)
						ans.push_back(ans[j]+1);
					for (int j=m-1;j>o;j--)
						ans.push_back(ans[j]);
					for (int j=m-1;j>o;j--)
						ans.push_back(ans[j]+1);
					for (int j=o;j>=0;j--)
						ans.push_back(ans[j]);
					break;
				}
			}
			break;
		}
	vis[u]=2;
}

variant<bool, vector<int>> find_journey(int n, int m, vector<int> U, vector<int> V)
{
	for (int i=0;i<m;i+=2)
		nei[U[i]].push_back(V[i]),ind[{U[i],V[i]}]=i;
	dfs(0);
	if (ans.size()) return ans;
	return false;
}

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