<p>There is a <strong>directed graph</strong> of <code>n</code> colored nodes and <code>m</code> edges. The nodes are numbered from <code>0</code> to <code>n - 1</code>.</p>

<p>You are given a string <code>colors</code> where <code>colors[i]</code> is a lowercase English letter representing the <strong>color</strong> of the <code>i<sup>th</sup></code> node in this graph (<strong>0-indexed</strong>). You are also given a 2D array <code>edges</code> where <code>edges[j] = [a<sub>j</sub>, b<sub>j</sub>]</code> indicates that there is a <strong>directed edge</strong> from node <code>a<sub>j</sub></code> to node <code>b<sub>j</sub></code>.</p>

<p>A valid <strong>path</strong> in the graph is a sequence of nodes <code>x<sub>1</sub> -&gt; x<sub>2</sub> -&gt; x<sub>3</sub> -&gt; ... -&gt; x<sub>k</sub></code> such that there is a directed edge from <code>x<sub>i</sub></code> to <code>x<sub>i+1</sub></code> for every <code>1 &lt;= i &lt; k</code>. The <strong>color value</strong> of the path is the number of nodes that are colored the <strong>most frequently</strong> occurring color along that path.</p>

<p>Return <em>the <strong>largest color value</strong> of any valid path in the given graph, or </em><code>-1</code><em> if the graph contains a cycle</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<p><img alt="" src="https://assets.leetcode.com/uploads/2021/04/21/leet1.png" style="width: 400px; height: 182px;" /></p>

<pre>
<strong>Input:</strong> colors = &quot;abaca&quot;, edges = [[0,1],[0,2],[2,3],[3,4]]
<strong>Output:</strong> 3
<strong>Explanation:</strong> The path 0 -&gt; 2 -&gt; 3 -&gt; 4 contains 3 nodes that are colored <code>&quot;a&quot; (red in the above image)</code>.
</pre>

<p><strong class="example">Example 2:</strong></p>

<p><img alt="" src="https://assets.leetcode.com/uploads/2021/04/21/leet2.png" style="width: 85px; height: 85px;" /></p>

<pre>
<strong>Input:</strong> colors = &quot;a&quot;, edges = [[0,0]]
<strong>Output:</strong> -1
<strong>Explanation:</strong> There is a cycle from 0 to 0.
</pre>

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

<ul>
	<li><code>n == colors.length</code></li>
	<li><code>m == edges.length</code></li>
	<li><code>1 &lt;= n &lt;= 10<sup>5</sup></code></li>
	<li><code>0 &lt;= m &lt;= 10<sup>5</sup></code></li>
	<li><code>colors</code> consists of lowercase English letters.</li>
	<li><code>0 &lt;= a<sub>j</sub>, b<sub>j</sub>&nbsp;&lt; n</code></li>
</ul>

#define pb push_back
class Solution {
public:
    int largestPathValue(string colors, vector<vector<int>>& edges) {

   int n = colors.length();

   int deg[n];
   memset(deg,0,sizeof(deg));

   vector<int>adj[n];
   for(auto ele:edges)
   {
      int u = ele[0];int v = ele[1];
      adj[u].pb(v);
      deg[v]++;
   }

   int cnt[n][26];
   memset(cnt,0,sizeof(cnt));

   queue<int>q;

   for(int i=0;i<n;i++)
   {
      if(deg[i]==0){
         q.push(i);
      }
      cnt[i][colors[i]-'a']++;
   }

   int ans = 0; int vis = 0;

   while(!q.empty())
   {
       int curr = q.front();q.pop();
       vis++;
       for(auto ele:adj[curr])
       {
           int cc = colors[ele]-'a';
           for(int i=0;i<26;i++)
           {
              cnt[ele][i] = max(cnt[ele][i] , cnt[curr][i] + (i==cc? 1:0));
           }

           deg[ele]--;
           if(deg[ele]==0)
           {
              q.push(ele);
           }
       }

       for(int i=0;i<26;i++)
       {
          ans = max(ans,cnt[curr][i]);
       }
   }

   if(vis!=n)
   {
      return -1;
   }

   return ans;
}
};
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