2-3 Trees
•2-3 trees permit the
number of children of an internal node
to vary between two and three.
•This feature allows us
to "absorb" insertions and deletions
without destroying the tree's shape.
–We can therefore search
a 2-3 tree almost as efficiently as you can
search a minimum-height binary search tree...and
it is far easier to maintain a 2-3 tree than it is to guarantee a binary search tree having minimum height.