Solved! Leetcode 129. Sum Root to Leaf Numbers

Description Sum Root to Leaf Numbers

You are given the root of a binary tree containing digits from 0 to 9 only.

Each root-to-leaf path in the tree represents a number.

  • For example, the root-to-leaf path 1 -> 2 -> 3 represents the number 123.

Return the total sum of all root-to-leaf numbers. Test cases are generated so that the answer will fit in a 32-bit integer.

leaf node is a node with no children.

Example 1

Example 2


  • The number of nodes in the tree is in the range [1, 1000].
  • 0 <= Node.val <= 9
  • The depth of the tree will not exceed 10.


Time Complexity

O(n): where n is the number of nodes in a binary tree

Space Complexity


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