Conditions -- K must satisfy


    1. level(N) even: 
  	all L in Tl, L.xval < K.xval
          all R in Tr, R.xval >= K.xval
  
    2. level(N) odd :
  	all L in Tl, L.yval < K.yval
          all R in Tr, R.yval >= K.yval
  

Heuristics - right subtree, Tr not empty

  • label(N) even, node with smallest xval in Tr
  • label(N) odd, node with smallest yval in Tr

left subtree

  • maximal xval or yval, must be unique

slide: Conditions -- replacement node