1. Binary trees preorder, inorder and postorder traversal problems.
   • Preorder and Inorder problem 28 from section 5.2 with an Eccentricity problem illustrating section 5.1 Graph theory and choosing the root for a tree based on Eccentricity.
   • Inorder and Postorder binary tree traversal exercise. Problem 29 of section 5.2 of the textbook by Judith Gersting.

2. How many functions from domain {a, b, c} to codomain {1, 2, 3} are NOT SURJECTIVE counting problem? Surjective means ONTO.

3. April 2000 QUIZ 3 practice quiz, including True/False textbook questions and Binary Tree Traversal questions.

4. Trees, permutations, Minimum Spanning Trees and Kruskal's algorithm for finding a MST from a connected, weighted graph. The 14 possible shapes for a 4 node binary tree and the 24 permutations of the letters in {a, b, c, d} mapping to the codomain of binary search trees.