Implementing the quick sort algorithm

Quick sort is one of the most popular sorting algorithms (see theIntroduction to sorting algorithms section) to implement, and it is also considered the most efficient in many cases.

Explanation of quick sort

The following visual shows you a high-level view of quick sort:

In this example, the algorithm chooses a pivot value, which in this case is 4. From there, it splits the collection into two groups: one with elements to the left of 4 and the other to the right of 4. Next, quick sort is recursively called on the newly formed left and right collections. For example, the group lower than 4 is chosen next and another pivot point for this subgroup is identified. Based on this pivot point, the array is sorted again. Likewise, the larger group goes through two smaller subgroups, and eventually, all the values are merged together to create a sorted list.

code example

Clear as mud? Don't worry if the concept is still a bit fuzzy. Quick sort isn't the most intuitive...