quicksort

function

 partition(array, left, right, pivotIndex)

     pivotValue := array[pivotIndex]

     swap array[pivotIndex] and array[right]  // Move pivot to end



     storeIndex := left

     for

 i  from 

 left to

 right - 1 // left ≤ i < right



         if

 array[i] < pivotValue

             swap array[i] and array[storeIndex]

             storeIndex := storeIndex + 1

     swap array[storeIndex] and array[right]  // Move pivot to its final place



     return

 storeIndex

function

 quicksort(array, left, right)

     if

 right > left  // subarray of 0 or 1 elements already sorted



         select a pivotIndex in the range left ≤ pivotIndex ≤ right  // see Choice of pivot for possible choices



         pivotNewIndex := partition(array, left, right, pivotIndex)  // element at pivotNewIndex is now at its final position



         quicksort(array, left, pivotNewIndex - 1)  // recursively sort elements on the left of pivotNewIndex



         quicksort(array, pivotNewIndex + 1, right)  // recursively sort elements on the right of pivotNewIndex