Data Structures and Algorithms
with Object-Oriented Design Patterns in C++ 
Since a leftist heap is a heap-ordered binary tree, it inherits from the BinaryTree base class the three member variables: key, left and right. The key is a pointer to the object contained in the given node and the left and right member variables point to the left and right subtrees of the given node, respectively. In addition, the member variable nullPathLength records the null path length of the given node. By recording the null path length in the node, it is possible to check the leftist heap balance condition in constant time.
Copyright © 1997 by Bruno R. Preiss, P.Eng. All rights reserved.