##### Wiktionary

**quicksort**

n. (context computing English) A sorting algorithm that operates by recursively partitioning the items to be sorted into two sets. vb. (context transitive computing English) To sort with such an algorithm.

##### Wikipedia

**Quicksort**

**Quicksort** (sometimes called **partition-exchange sort**) is an efficient sorting algorithm, serving as a systematic method for placing the elements of an array in order. Developed by Tony Hoare in 1959, with his work published in 1961, it is still a commonly used algorithm for sorting. When implemented well, it can be about two or three times faster than its main competitors, merge sort and heapsort.

Quicksort is a comparison sort, meaning that it can sort items of any type for which a "less-than" relation (formally, a total order) is defined. In efficient implementations it is not a stable sort, meaning that the relative order of equal sort items is not preserved. Quicksort can operate in-place on an array, requiring small additional amounts of memory to perform the sorting.

Mathematical analysis of quicksort shows that, on average, the algorithm takes O(*n* log *n*) comparisons to sort *n* items. In the worst case, it makes O(*n*) comparisons, though this behavior is rare.