Balanced BST

A balanced binary search tree implementation with Vanilla Javascript.

• Create a new Binary Search Tree instance with the new Tree(arr) call. arr is an array provided by the user which might have duplicate items and don't have to be sorted. Cleaning and sorting the data is handled by the Tree class.

• insertNode(key) instance method insert a new node into the BST, which has the "key" provided by user as it's key property.

• deleteNode(key) instance method removes the node with the given key from the BST.

• find(value) method accepts a value and returns the node with the given value, if it exists. Otherwise returns an an appropriate error.

• levelOrder, inOrder, preOrder, and postOrder methods accept an optional callback function as its parameter. levelOrder traverses the tree in breadth-first level order and provides a level ordered array of nodes. Each of inOrder, preOrder, and postOrder functions traverse the tree in their respective depth-first order and provide an ordered array of nodes. The functions returns an array of values if no callback is given as an argument.

• getNodeHeight(key) method accepts a node and returns its height. Height is defined as the number of edges in the longest path from a given node to a leaf node.

• getNodeDepth(key) method accepts a node and returns its depth. Depth is defined as the number of edges in the path from a given node to the tree’s root node.

• isBalanced() method checks if the tree is balanced. A balanced tree is one where the difference between heights of the left subtree and the right subtree of every node is not more than 1.

• rebalance() method rebalances an unbalanced tree.

• Also, the prettyPrint(node) utility function can be used to log the BST to the console in a more pleasant way. The node parameter should be the root of the Tree class instance.