Items of interest

• There are two such cases:

  • The case shown, where “outer” is defined as the left subtree of the left subtree. fixed by a single right rotation at the root node of the unbalanced subtree.
  • The case not shown, where “outer” is defined as the right subtree of the right subtree. (mirror of the case shown) Fixed by a single left rotation.

• This is the most basic case that is fixed by a single rotation.