The quick sort.

The quicksort algorithm partitions an array of data into items that are less than the pivot and those that are greater than or equal to the pivot item. The first step is to create the partitions, in which a random pivot item is created, and the partition algorithm is applied to the array of items. This initial step is the most difficult part of the quicksort algorithm. The basic idea of the partitioning is that there are three regions: S1, S2, and the unknown. Each item from the unknown is placed into the appropriate region. Then the pivot is moved in between the two regions. The recursive quicksort algorithm works by applying the partition algorithm to each previously created partition until the entire array is sorted. Advantages include the efficient average case compared to any aforementioned sort algorithm, as well as the elegant recusrive definition, and the popularity due to its high efficiency. Disadvantages include the difficulty of implementing the partitioning algorithm and the average efficiency for the worst case scenario, which is not offset by the difficult implementation.