Authors:
Stuart Reges, Marty Stepp
Chapter:
Binary Trees
Exercise:
Exercises
Question:2 | ISBN:9780136091813 | Edition: 2
Question
Write a method called countLeftNodes that returns the number of left children in the tree. A left child is a node that appears as the root of the left-hand subtree of another node.
Add the above method to the IntTree class from this chapter. You may define additional private methods to implement your public method if necessary. Several problem descriptions refer to the following reference binary trees:
For example, reference tree #1 has 3 left children (the nodes storing the values 5 , 1 , and 4 ).
Answer
Implementation of countLeftNodes method:
public int countLeftNodes()
{
return countLeftNodes(overallRoot);
}
private int countLeftNodes(IntTreeNode root)
{
if(root == null)
return 0;
int count = 0;
if(root.left != null)
count += 1 + countLeftNodes(root.left);
if(root.right != null)
count += countLeftNodes(root.right);
return count;
}