1448. Count Good Nodes in Binary Tree

Author: VinayByte

1448.CountGoodNodesinBinaryTree.kt

@@ -0,0 +1,31 @@
+/**
+ * Example:
+ * var ti = TreeNode(5)
+ * var v = ti.`val`
+ * Definition for a binary tree node.
+ * class TreeNode(var `val`: Int) {
+ *     var left: TreeNode? = null
+ *     var right: TreeNode? = null
+ * }
+ */
+//https://leetcode.com/problems/count-good-nodes-in-binary-tree/description
+class Solution {
+    var count = 0
+    fun goodNodes(root: TreeNode?): Int {
+        goodNodeCount(root, Int.MIN_VALUE)
+        return count
+    }
+
+    fun goodNodeCount(node: TreeNode?, maxParent: Int){
+        if(node == null) return
+
+        val isGoodNode = node.`val` >= maxParent
+        if(isGoodNode){
+            count++
+        }
+
+        val currentMax = maxOf(maxParent, node.`val`)
+        goodNodeCount(node.left, currentMax)
+        goodNodeCount(node.right, currentMax)
+    }
+}