Description
Given the root of a binary tree, return the sum of values of its deepest leaves.
Example 1:
Input: root = [1,2,3,4,5,null,6,7,null,null,null,null,8] Output: 15
Example 2:
Input: root = [6,7,8,2,7,1,3,9,null,1,4,null,null,null,5] Output: 19
Constraints:
- The number of nodes in the tree is in the range
[1, 104]. 1 <= Node.val <= 100
Solution
Python3
# 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 deepestLeavesSum(self, root: TreeNode) -> int:
def depth(node):
if not node: return 0
return 1 + max(depth(node.left), depth(node.right))
d = depth(root)
res = 0
q = collections.deque([(root, 1)])
while q:
node, depth = q.popleft()
if depth == d: res += node.val
for leaf in (node.left, node.right):
if leaf:
q.append((leaf, depth + 1))
return res