# 513. Find Bottom Left Tree Value """ given the 'root' of a binary tree, return the leftmost value in the last row of the tree """ class TreeNode(object): def __init__(self, val=0, left=None, right=None): self.val = val self.left = left self.right = right class Solution(object): def findBottomLeftValue(self, root): queue = [root] for node in queue: queue += filter(None, (node.right, node.left)) return node.val