# CocktailSort (take 2)

We will now apply to CocktailSort the same optimization than BubbleSort2 did to BubbleSort. We must remember the limits of the array part not being sorted yet, and traverse it alternatively from left to right and from right to left:

    beg=0; end=len-2
    do
      For all Pour i in [beg,end], do:
          If cells i and i+1 must be swapped, do it
      end -= 1 (this means end = end - 1)
      For all Pour i in [beg,end] (downwards), do:
          If cells i and i+1 must be swapped, do it
      beg += 1 (this means beg = beg + 1)
    while at least one of the traversal swapped an element