Time: 99 ms (41.59%), Space: 120.4 MB (43.86%) - LeetHub

Author: Sangram03

1986-largest-color-value-in-a-directed-graph/1986-largest-color-value-in-a-directed-graph.java

@@ -0,0 +1,43 @@
+class Solution {
+    private static final int INF = Integer.MAX_VALUE;
+    public int largestPathValue(String colors, int[][] edges) {
+        int n = colors.length();
+        List<List<Integer>> adj = new ArrayList<>();
+        for (int i = 0; i < n; i++)
+            adj.add(new ArrayList<>());
+        for (int[] e : edges)
+            adj.get(e[0]).add(e[1]);
+            
+        int[][] count = new int[n][26];
+        int[] vis = new int[n];
+        int ans = 0;
+
+        for (int i = 0; i < n && ans != INF; i++) {
+            ans = Math.max(ans, dfs(i, colors, adj, count, vis));
+        }
+        return ans == INF ? -1 : ans;
+    }
+
+    private int dfs(int node, String colors,List<List<Integer>> adj,int[][] count,int[] vis) {
+        if (vis[node] == 1)
+            return INF;
+        if (vis[node] == 2) {
+            return count[node][colors.charAt(node) - 'a'];
+        }
+
+        vis[node] = 1;
+        for (int nxt : adj.get(node)) {
+            int res = dfs(nxt, colors, adj, count, vis);
+            if (res == INF)
+                return INF;
+            for (int c = 0; c < 26; c++) {
+                count[node][c] = Math.max(count[node][c], count[nxt][c]);
+            }
+        }
+        int col = colors.charAt(node) - 'a';
+        count[node][col]++;
+        vis[node] = 2;
+
+        return count[node][col];
+    }
+}