2. Algorithms - Quick Sort

Quicksort, sorts an array recursively by picking a pivot point (usually the middle element). Then creating two subArrays left and right of the pivot. Left would contain elements in array that is less than pivot, and right is greater.

subArrays are put into quicksort again with base statement returning an array with length of 1 or 0.

package main

//import "fmt"

func quickSort(list []int) []int {
    if len(list) <= 1 {
        return list
    }

    pivot := make([]int, 1)
    pivot[0] = list[0]
    leftList := []int{}
    rightList := []int{}

    for i := 1; i < len(list); i++ {
        if list[i] > pivot[0] {
            rightList = append(rightList, list[i])
        } else {
            leftList = append(leftList, list[i])
        }
    }

    leftSublist := quickSort(leftList)
    rightSublist := quickSort(rightList)

    answer := []int{}
    answer = append(leftSublist, pivot...)
    answer = append(answer, rightSublist...)
    return answer
}

/*func main() {
    x := []int{4, 6, 3, 2, 9, 7, 3, 5}
    fmt.Println(quickSort(x))
}*/



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