name the 3 ways of traversing a tree
how does preorder work
1) visits the root
2) traverses to the left subtree
3) traverses to the right subtree
how does postorder work
1) traverses to the left subtree
2) traverses to the right subtree
3) visits the root
how does inorder work
1) traverses to the left subtree
2) visits the root
3) traverses to the right subtree