513. Find Bottom Left Tree Value
Medium
Given the root of a binary tree, return the leftmost value in the last row of the tree.
Example 1:
Input: root = [2,1,3] Output: 1
Example 2:
Input: root = [1,2,3,4,null,5,6,null,null,7] Output: 7
Constraints:
- The number of nodes in the tree is in the range
[1, 104]. -231 <= Node.val <= 231 - 1
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, val=0, left=None, right=None):
# self.val = val
# self.left = left
# self.right = right
class Solution:
def findBottomLeftValue(self, root):
queue = deque()
current = root
queue.append(current)
while queue:
current = queue.popleft()
if current.right:
queue.append(current.right)
if current.left:
queue.append(current.left)
return current.val