Find 4 Largest

find4Largest.swift

import UIKit

func find4Largest(numbers:[Int]) -> [Int]
{
    let count = 4
    assert(count < numbers.count, "Error: numbers must have at least \(count) elements")
    if numbers.count < 2
    {
        return numbers
    }
    var results = [numbers[0],0,0,0]
    for number in numbers
    {
        var newNumber = number
        for var index = 0; index < count; ++index
        {
            let current = results[index]
            if newNumber > current
            {
                results[index] = newNumber
                newNumber = current
            }
        }
    }
    return results
}

/*
// uncomment this in a playground to see the demonstration

var array1 = [2,6,1,4,8,3,0,9,5,7]
find4Largest(array1)

var array2 = [Int]()
for _ in 0..<100
{
    array2.append(Int(arc4random_uniform(1000)))
}
array2

find4Largest(array2)
*/

Copy and paste this into an iOS swift playground.