Leetcode 173: Binary Search Tree Iterator - facebook code lab

July 18, 2016

Problem statement:

Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.

The first call to next() will return the smallest number in BST. Calling next() again will return the next smallest number in the BST, and so on.

Note: next() and hasNext() should run in average O(1) time and uses O(h)memory, where h is the height of the tree.
Try to optimize the additional space complexity apart from the amortized time complexity.

The time estimated is 41 minutes in facebook code lab.

Plan to work on this problem in short future.