Merge pull request neetcode-gh#525 from kciccolella/leetcode124

Create 124-Binary-Tree-Maximum-Path-Sum.js

javascript/124-Binary-Tree-Maximum-Path-Sum.js

@@ -0,0 +1,35 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ * this.val = (val===undefined ? 0 : val)
+ * this.left = (left===undefined ? null : left)
+ * this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+var maxPathSum = function(root) {
+ const res = [root.val];
+
+ // return max path sum without split
+ function dfs(root) {
+ if (!root) {
+ return 0;
+ }
+
+ let leftMax = dfs(root.left);
+ let rightMax = dfs(root.right);
+ leftMax = Math.max(leftMax, 0);
+ rightMax = Math.max(rightMax, 0);
+
+ // compute max path sum WITH split
+ res[0] = Math.max(res[0], root.val + leftMax + rightMax);
+
+ return root.val + Math.max(leftMax, rightMax);
+ }
+
+ dfs(root);
+ return res[0]; 
+};