Introduction

Here’s one task related to the tree data structure. Given two nodes, can you find their lowest common ancestor?

In a matter of fact this task always has a proper solution, because at least the root node is a common ancestor of all pairs of nodes. However here the task is to find the lowest one, which can be quite far from the root.

We don’t care what kind of trees we have. However the solution, as we will see, can be very different depending on the tree type. Indeed finding the lowest common ancestor can have linear complexity for binary search trees, which isn’t true for ordinary trees. Continue reading Computer Algorithms: Finding the Lowest Common Ancestor →