Branch Sums - algoexpert.io

branchSums.py

"""
https://www.algoexpert.io/questions/Branch%20Sums
"""

class BinaryTree:
    def __init__(self, value):
        self.value = value
        self.left = None
        self.right = None

"""
O(n) time | O(n) space
n = number of nodes in BinaryTree
"""
def branchSums(root):
    sums = []
	recurseBranchSums(root, 0, sums)
	return sums

def recurseBranchSums(node, currentSum, sums):
	if node is None:
		return
	
	currentSum += node.value
	if node.left is None and node.right is None:
		sums.append(currentSum)
		return
	
	recurseBranchSums(node.left, currentSum, sums)
	recurseBranchSums(node.right, currentSum, sums)