<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>
class Solution:

    def largestPathValue(self, colors: str, edges: List[List[int]]) -> int:

        n = len(colors)
        adjList = defaultdict(list)
        
        for f, t in edges:
            adjList[f].append(t)
        
        parentSet = set()
        ans = 1
        cycleFound = False

        cache = {}
        defaultColorsList = [0] * 26

        def dfs(node, parentSet) -> List[int]:

            nonlocal ans, cycleFound
            
            if cycleFound: return defaultColorsList
            if node in parentSet:
                cycleFound = True
                return defaultColorsList

            if node in cache: return cache[node]
            
            parentSet.add(node)

            maxColorFreq = [1 if i == (ord(colors[node])-ord('a')) else 0 for i in range(26)]
            
            # adj
            for adjNode in adjList[node]:
                maxChildColorFreq = dfs(adjNode, parentSet)
                for i in range(26):
                    maxColorFreq[i] = max(maxChildColorFreq[i] + (1 if i == (ord(colors[node])-ord('a')) else 0), maxColorFreq[i])
                    ans = max(ans, maxColorFreq[i])
            

            cache[node] = maxColorFreq
            
            parentSet.remove(node)

            return cache[node]

        
        # if not indegreeZeroNodes: return -1
        
        for node in range(n):
            dfs(node, parentSet)

        print(f'{cycleFound=}')
        if cycleFound == True: return -1

        return ans if ans > 0 else -1



    # def largestPathValue(self, colors: str, edges: List[List[int]]) -> int:

    #     adjList = defaultdict(list)
    #     indegreeZeroNodes = set(range(len(colors)))
    #     outdegreeZeroNodes = set(range(len(colors)))
        
    #     for f, t in edges:
    #         adjList[f].append(t)
    #         indegreeZeroNodes.discard(t)
    #         outdegreeZeroNodes.discard(f)
        
    #     parentSet = set()
    #     ans = 0

    #     def dfs(node, colorFreq, parentSet):

    #         nonlocal ans
            
    #         if ans == -1: return

    #         if node in parentSet:
    #             ans = -1
    #             return

    #         if node in outdegreeZeroNodes:
    #             updatedColorFreq = colorFreq[:]
    #             updatedColorFreq[ord(colors[node]) - ord('a')] += 1
    #             ans = max(ans, max(updatedColorFreq))
    #             return
            
    #         parentSet.add(node)
    #         colorFreq[ord(colors[node]) - ord('a')] += 1

    #         # adj
    #         for adjNode in adjList[node]:
    #             dfs(adjNode, colorFreq, parentSet)
            
    #         parentSet.remove(node)
    #         colorFreq[ord(colors[node]) - ord('a')] -= 1

    #         return

        
    #     for node in indegreeZeroNodes:
    #         colorFreq = [0 for _ in range(26)]
    #         dfs(node, colorFreq, parentSet)

    #     return ans if ans > 0 else -1
125385