<p>You are given a <strong>directed</strong> graph of <code>n</code> nodes numbered from <code>0</code> to <code>n - 1</code>, where each node has <strong>at most one</strong> outgoing edge.</p>

<p>The graph is represented with a given <strong>0-indexed</strong> array <code>edges</code> of size <code>n</code>, indicating that there is a directed edge from node <code>i</code> to node <code>edges[i]</code>. If there is no outgoing edge from node <code>i</code>, then <code>edges[i] == -1</code>.</p>

<p>Return <em>the length of the <strong>longest</strong> cycle in the graph</em>. If no cycle exists, return <code>-1</code>.</p>

<p>A cycle is a path that starts and ends at the <strong>same</strong> node.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/06/08/graph4drawio-5.png" style="width: 335px; height: 191px;" />
<pre>
<strong>Input:</strong> edges = [3,3,4,2,3]
<strong>Output:</strong> 3
<strong>Explanation:</strong> The longest cycle in the graph is the cycle: 2 -&gt; 4 -&gt; 3 -&gt; 2.
The length of this cycle is 3, so 3 is returned.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/06/07/graph4drawio-1.png" style="width: 171px; height: 161px;" />
<pre>
<strong>Input:</strong> edges = [2,-1,3,1]
<strong>Output:</strong> -1
<strong>Explanation:</strong> There are no cycles in this graph.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>n == edges.length</code></li>
	<li><code>2 &lt;= n &lt;= 10<sup>5</sup></code></li>
	<li><code>-1 &lt;= edges[i] &lt; n</code></li>
	<li><code>edges[i] != i</code></li>
</ul>

class Solution {
public:
int ans = -1;

    void dfs(int i,vector<int>&vis,vector<int>&v,vector<int>& edges){
        if(i==-1)return ;
        if(vis[i]){
            cout<<"vis "<<i<<endl;
            for(auto i:v)cout<<i<<" ";
            cout<<endl;
            int ind=-1 ;
            for(int k = 0;k<v.size();k++){
                if(v[k] == i){ind = k;break;}
            }
            if(ind == -1)return ;
            int sz = v.size()-ind;
            cout<<"sz "<<sz<<endl;
            if(sz>ans)ans = sz;
            return;

        }
        vis[i]=1;
        v.push_back(i);
        dfs(edges[i],vis,v,edges);

        
    }
    int longestCycle(vector<int>& edges) {
        int n = edges.size();
        
        vector<int>dist(n,-1),in(n,-1),vis(n);
        
        
        for(int i = 0;i<n;i++){
            if(!vis[i] && edges[i]!=-1){
                vector<int>v;
               
                dfs(i,vis,v,edges);
            }
        }
        return ans;

        
    }
};
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