Array to Tree Algorithm
Managing data almost always involves working with hierarchical or nested data. Whether we are talking about nested files and folders, product categories and sub-categories, music, ... you name it. But we store data in a database in a flat structure. This makes sense because the data objects themselves share the same attributes and it makes for easy searching. But how we store the data and how we need to visualize and manipulate it don't necessarily match. So how do we efficiently transform a flat array to a tree? Day 5 of 30 Days of Algorithms will present one solution with O(n) complexity.

