Create a method named countChildSumToNegative
that
accepts a single BinaryTree<Int>?
and counts the number of nodes in the tree where the values of node's
children sum to a negative number.
You should not count nodes that don't have at least one child, but some nodes may only have one child.
Keep in mind that not every node has a right or left child, so you'll need to check for null
carefully.
However, you can assume that all the values in the tree are Int
s.
For reference, cs125.trees.BinaryTree
is defined like this:
Stuck? You may find these lessons helpful: