Swift Sleep Sort

SleepSort.swift

import Foundation

// O(n) sort
// Technically O(n) since time measures complexity and not a fixed interval
// NOTE: This is just for fun, please don't use this in real applications!
func sleepSort(_ vals: [Int]) -> [Int] {
	var result: [Int] = []
	let sortDispatch = DispatchQueue(label: "sleepSort", qos: .userInitiated, attributes: .concurrent)
	let sortGroup = DispatchGroup()
	
	_ = vals.map { val in
		sortDispatch.async(group: sortGroup) {
			sleep(UInt32(val))
			result.append(val)
		}
	}
	sortGroup.wait()
	return result
}

print(sleepSort([4,1,3,2]))