Wiggle the towerWiggle the tower

code-golf

Your input is the height map of a tower. The tower is made out of layers, each one being one unit shorter than the one below it. Every layer is completely on top of the previous layer. For example [1,4,5,3,2] is a valid input. Here is a visualization:

  #
 ##
 ###
 ####
#####

14532

Your task is to wiggle the tower. Wiggling works as from top to bottom. We shift a layer to the left, or if this is not possible, shift the layer to the right and repeat for the next layer.

Here is how this input would be wiggled.

  #
 ##
 ###
 ####
#####
14532

 #
 ##
 ###
 ####
#####
15432

   #
  ##
 ###
####
#####
23451

  #
  ##
 ###
####
#####
23541

  #
 ##
 ###
####
#####
24531

 #
 ##
 ###
####
#####
25431

  #
 ##
###
####
#####
34521

So if your program got [1,4,5,3,2] it should return [1,5,4,3,2].