Finding the maximum depth of a binary tree

The maximum depth of a binary tree is the number of nodes from the root down to the furthest leaf node. In other words, it is the height of a binary tree.

Consider the binary tree illustrated below:



The maximum depth, or height, of this tree is 44; node 77 and node 88 are both four nodes away from the root.

Algorithm

The algorithm uses recursion to calculate the maximum height:

1. Recursively calculate the height of the tree to the left of the root.
2. Recursively calculate the height of the tree to the right of the root.
3. Pick the larger height from the two answers and add one to it (to account for the root node).