Binary Trees
http://cslibrary.stanford.edu/110/BinaryTrees.html

A very good collection of problems on Binary Tree

Binary Trees

by Nick Parlante

This article introduces the basic concepts of binary trees, and then works through a series of practice problems with solution code in C/C++ and Java. Binary trees have an elegant recursive pointer structure, so they are a good way to learn recursive pointer algorithms.

Contents

Section 1. Binary Tree Structure -- a quick introduction to binary trees and the code that operates on them
Section 2. Binary Tree Problems -- practice problems in increasing order of difficulty
Section 3. C Solutions -- solution code to the problems for C and C++ programmers
Section 4. Java versions -- how binary trees work in Java, with solution code