sec binary tree node implementations figure illustration of typical pointer-based binary tree implementationwhere each node stores two child pointers and value figure an expression tree for ( ac larger to handle the wider range of possible values at the same timeleaf nodes need not store child pointers java allows us to differentiate leaf from internal nodes through the use of class inheritance as we have seen with lists and with class binnodea base class provides general definition for an objectand subclass modifies base class to add more detail base class can be declared for nodes in generalwith subclasses defined for the internal and leaf nodes the base class of figure is named varbinnode it includes virtual member function named isleafwhich indicates the node type subclasses for the internal and leaf node types each implement isleaf internal nodes store child pointers of the base class typethey do not distinguish their children' actual subclass whenever node is examinedits version of isleaf indicates the node' subclass