Balanced Binary Tree

Author: parshva45

Diff for: Balanced Binary Tree.js

@@ -0,0 +1,55 @@
+/*Given a binary tree, determine if it is height-balanced.
+
+For this problem, a height-balanced binary tree is defined as:
+
+a binary tree in which the depth of the two subtrees of every node never differ by more than 1.
+
+Example 1:
+
+Given the following tree [3,9,20,null,null,15,7]:
+
+    3
+   / \
+  9  20
+    /  \
+   15   7
+Return true.
+
+Example 2:
+
+Given the following tree [1,2,2,3,3,null,null,4,4]:
+
+       1
+      / \
+     2   2
+    / \
+   3   3
+  / \
+ 4   4
+Return false.*/
+
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {boolean}
+ */
+var isBalanced = function(root) {
+    if(root == null)
+        return true
+    var diff = depth(root.left) - depth(root.right)
+    if(Math.abs(diff) > 1)
+        return false
+    return isBalanced(root.left) && isBalanced(root.right)
+};
+
+var depth = function(node){
+    if(node == null)
+        return 0
+    return 1 + Math.max(depth(node.left), depth(node.right))
+}