Binary Trees in Java and their methods

Question description

1. Extend the class BinaryTree to include a boolean method that determines whether a binary tree is a
   BST.

ANSWER:

public boolean isBinarySearchTree() {
return isBST(root);

}

//helper method called by isBinarySearchTree

public boolean isBST(BinaryTreeNode tree){
…

}

2. Extend the class BinaryTree to include a boolean method similarTrees that determines whether the
   shapes of two trees are the same (the nodes do not have to contain the same values, but each node must
   have the same number of children)

ANSWER:

public boolean similarTrees(BinaryTreeNode otherTree) {
return similar(root, otherTree);

}

//helper method called by similarTrees

public boolean similar(BinaryTreeNode tree1, BinaryTreeNode tree2) {
…

}

3­&4. Extend the class BinaryTree to include 2 more methods: nodeCount (count the number of leaves
in a binary tree) and leavesCount (count the number of nodes in a binary tree). Use recursion in both!
Add statements to the client program (lecture notes) to test these new added methods.

ANSWER:

public int treeLeavesCount() {
return leavesCount(root);

}

//helper method called by treeLeavesCount

private int leavesCount(BinaryTreeNode t) {
…

}

}

//helper method called by treeNodeCount

private int nodeCount(BinaryTreeNode t) {
…

}