Count Complete Tree Nodes

Problem

Count the nodes of a complete binary tree given in level order.

tree is a list where real values are nodes and None marks missing positions; trailing Nones may be omitted.

Return the number of non-None entries.

Hint

In a complete tree every value present in the level-order list is a node.

case 1

in: [[1,2,3,4,5,6]]

expected: 6

case 2

in: [[]]

expected: 0

case 3

in: [[1]]

expected: 1

case 4

in: [[1,null,2]]

expected: 2

Starter codePython

def count_complete_nodes(tree):
    # Your code here
    pass

4 test cases · run your code against them in the editor