Create 124-binary-tree-maximum-path-sum.js

Author: everthis

124-binary-tree-maximum-path-sum.js

@@ -0,0 +1,28 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+const maxPathSum = function(root) {
+  let obj = {
+    max: Number.MIN_SAFE_INTEGER
+  }
+  traverse(root, obj)
+  
+  return obj.max
+};
+
+function traverse(node, obj) {
+  if(node === null) return 0
+  let left = Math.max(0, traverse(node.left, obj))
+  let right = Math.max(0, traverse(node.right, obj))
+  obj.max = Math.max(obj.max, node.val+left+right)
+  return node.val + Math.max(left, right)
+}
+