Merge pull request neetcode-gh#958 from MaratKhakim/124-BT-Max-Path-Kt

Kotlin: 124. Binary Tree Maximum Path Sum

kotlin/124-Binary-Tree-Maximumu-Path-Sum.kt

@@ -0,0 +1,28 @@
+/**
+ * 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
+ * }
+ */
+class Solution {
+ fun maxPathSum(root: TreeNode?): Int {
+ val res = IntArray(1) {Int.MIN_VALUE}
+ maxPathSum(root, res)
+ return res[0]
+ }
+
+ fun maxPathSum(root: TreeNode?, res: IntArray): Int {
+ if (root == null)
+ return 0
+
+ val left = Math.max(0, maxPathSum(root.left, res))
+ val right = Math.max(0, maxPathSum(root.right, res))
+ res[0] = Math.max(res[0], root.`val` + left + right)
+
+ return root.`val` + Math.max(left, right)
+ }
+}