Create 0129-sum-root-to-leaf-numbers.js

Author: aadil42

Diff for: javascript/0129-sum-root-to-leaf-numbers.js

@@ -0,0 +1,32 @@
+/**
+ * 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)
+ * }
+ */
+/**
+ * Tree | pre-order-traversal
+ * Time O(n) | Space O(n)
+ * https://leetcode.com/problems/sum-root-to-leaf-numbers
+ * @param {TreeNode} root
+ * @return {number}
+ */
+var sumNumbers = function(root) {
+    
+  let total = 0;
+  const dfs = (node, num) => {
+      if(!node.left && !node.right) {
+          num = num+node.val;
+          total += +num;
+          return;
+      }
+
+      node.left && dfs(node.left, num+node.val);
+      node.right && dfs(node.right, num+node.val);
+  }
+
+  dfs(root,"");
+  return total;
+};