graphviz, straighten out skiplist?

I have a digraph made up to draw a skiplist, which it does fairly well, but the alignment needs to be improved.

digraph {
  rankdir=LR
  node [shape=record,weight=4]
  edge [weight=10000]

  X [label="<f0>•|<f1>•|<f2>•|<f3>•|<f4>Head"]
  A [label="<f3>•|<f4>4"]
  B [label="<f1>•|<f2>•|<f3>•|<f4>8"]
  C [label="<f3>•|<f4>15"]
  D [label="<f0>•|<f1>•|<f2>•|<f3>•|<f4>16"]
  E [label="<f2>•|<f3>•|<f4>23"]
  F [label="<f2>•|<f3>•|<f4>42"]
  Y [label="<f0>•|<f1>•|<f2>•|<f3>•|<f4>Tail"]

  X:f0 -> D:f0
  X:f1 -> B:f1
  X:f2 -> B:f2
  X:f3 -> A:f3
  X:f4 -> A:f4

  A:f3 -> B:f3
  A:f4 -> B:f4

  B:f1 -> D:f1
  B:f2 -> D:f2
  B:f3 -> C:f3
  B:f4 -> C:f4

  C:f3 -> D:f3
  C:f4 -> D:f4

  D:f0 -> Y:f0
  D:f1 -> Y:f1
  D:f2 -> E:f2
  D:f3 -> E:f3
  D:f4 -> E:f4

  E:f3 -> F:f3
  E:f4 -> F:f4

  F:f2 -> Y:f2
  F:f3 -> Y:f3
  F:f4 -> Y:f4
}

This produces:

I would like to produce something more like this:

How do I make the edges be straight? And how do align the nodes to be all on the same baseline?

Solution

For this graph, all that needs to be done is to add this to the graph:

nodesep=0

(You then may also remove the weight attributes)

nodesep: specifies the minimum space between two adjacent nodes in the same rank

The way I imagine it works, is that nodesep adds some padding to the sides of the nodes. If there is a nearby edge, the node will be moved to respect the padding.