Merge sort algorithm

mergesort.swift

var array2 = [4,2,2,5,7,2,1,9,3]


func merge(left:[Int],right:[Int]) -> [Int] {
    var mergedList = [Int]()
    var l = left
    var r = right
    
    while l.count > 0 && r.count > 0 {
        if l.first! < r.first! {
            mergedList.append(l.removeFirst())
        } else {
            mergedList.append(r.removeFirst())
        }
    }

    return mergedList + l + r
}

func mergeSort(list:[Int]) -> [Int] {
    guard list.count > 1 else {
        return list
    }
    
    let leftList = Array(list[0..<list.count/2])
    let rightList = Array(list[list.count/2..<list.count])
    
    return merge(left: mergeSort(list:leftList), right: mergeSort(list:rightList))
}

print(mergeSort(list: array2))