Quicksort and mergesort

gistfile1.coffee

mergesort = (->
  merge = (x, y, acc = []) ->
    if x.length == 0
      acc.concat(y)
    else if y.length == 0
      acc.concat(x)
    else if x[0] < y[0]
      merge x[1..-1], y, acc.concat x[0]
    else
      merge x, y[1..-1], acc.concat y[0]

  sort = (a) ->
    return a if a.length <= 1
    left = a[0...a.length/2]
    right = a[a.length/2...a.length]
    merge sort(left), sort(right)
)()

quicksort = (->
  sort = (a) ->
    return a if a.length <= 1
    pivot = a[0]
    lesser = a[1..-1].filter (n) -> n < pivot
    greater = a[1..-1].filter (n) -> n >= pivot
    sort(lesser).concat [pivot], sort(greater)
)()

numbers = [5,2,3,1,4]

console.log mergesort(numbers) # => [1,2,3,4,5]
console.log quicksort(numbers) # => [1,2,3,4,5]