1302. Deepest Leaves Sum

Medium

---

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

# 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: Optional[TreeNode]) -> int:
        if not root:
            return 0
        total = 0
        temp = 0
        q = deque()
        q.append(root)
        q.append("#")
        while q:
            node = q.popleft()
            if node == '#':
                total = temp
                temp = 0
                if len(q) != 0:
                    q.append("#")
                continue
            temp += node.val
            if node.left:
                q.append(node.left)
            if node.right:
                q.append(node.right)
        return total