Binary Search Trees
From 6.006 Introduction to Algorithms
This page contains various implementations of different Binary Search Trees (BSTs).
Simple BST (no balancing)
- bst.py
- Features: insert, find, delete_min, ASCII art
- bstsize.py
- Imports and extends bst.py
- Augmentation to compute subtree sizes
- bstsize_r.py
- Recursive version from recitation for computing subtree sizes
- Features: insert, find, rank, delete
AVL tree
Testing
Both bst.py and avl.py (as well as bstsize.py) can be tested interactively from a UNIX shell as follows:
-
python bst.py 10
— do 10 random insertions, printing BST at each step -
python avl.py 10
— do 10 random insertions, printing AVL tree at each step
Alternatively, you can use them from a Python shell as follows:
>>> import bst >>> t = bst.BST() >>> print t <empty tree> >>> for i in range(4): ... t.insert(i); ... >>> print t 0 /\ 1 /\ 2 /\ 3 /\ >>> t.delete_min() >>> print t 1 /\ 2 /\ 3 /\
>>> import avl >>> t = avl.AVL() >>> print t <empty tree> >>> for i in range(4): ... t.insert(i); ... >>> print t 1 / \ 0 2 /\ /\ 3 /\ >>> t.delete_min() >>> print t 2 / \ 1 3 /\ /\