quicksort.swift

// Playground - noun: a place where people can play

import UIKit

let b = [1, 2, 3][1..2].filter { $0 < 3 }
let c = b + [5, 6]

func quicksort<T : Comparable>(arr : Array<T>) -> Array<T> {
    if arr.count <= 1 {
        return arr
    }

    let pivot = arr[0]
    let tail = arr[1..arr.count]
    let lesser = tail.filter { $0 < pivot }
    let greater = tail.filter { $0 >= pivot }
    return quicksort(lesser) + [pivot] + quicksort(greater)
}


//quicksort([3, 5, 2, 1])