#404

Sum of Left Leaves

pupil · 355 · lc easy +23 · verified · 62.4% accepted · 5,782 likes · top 64%

Description

Given the root of a binary tree, add up the values of all left leaves and return the total. A leaf is a node with no children; a left leaf is a leaf that is the left child of some other node.

Example 1:

Input: root = [3,9,20,null,null,15,7]

Output: 24

Explanation: There are two left leaves in the binary tree, with values 9 and 15 respectively.

Example 2:

Input: root = [1]

Output: 0

Code

# 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 sumOfLeftLeaves(self, root: Optional[TreeNode]) -> int:

# 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 sumOfLeftLeaves(self, root: Optional[TreeNode]) -> int: