Binary search tree: remove node

General Information

Algorithmic problem: See the remark clause of Binary Search Tree; pointer p as defined there is the input.

Prerequisites: [math]\displaystyle{ p.left \neq void }[/math]

Type of algorithm: loop

Auxiliary data: A pointer [math]\displaystyle{ p' }[/math] of type "pointer to a binary search tree node".

Abstract View

Invariant:

1. The immediate predecessor of K is in the range of [math]\displaystyle{ p' }[/math].
2. It is [math]\displaystyle{ p'.right = void }[/math].

Variant: The pointer [math]\displaystyle{ p' }[/math] descends one level deeper to [math]\displaystyle{ p'.right }[/math].

Break condition: It is [math]\displaystyle{ p'.right.right = void }[/math].