# LeetCode — Sum of Root to Leaf Binary Numbers

You are given the `root`

of a binary tree where each node has a value `0`

or `1`

. Each root-to-leaf path represents a binary number starting with the most significant bit. For example, if the path is `0 -> 1 -> 1 -> 0 -> 1`

, then this could represent `01101`

in binary, which is `13`

.

For all leaves in the tree, consider the numbers represented by the path from the root to that leaf.

Return *the sum of these numbers*. The answer is **guaranteed** to fit in a **32-bits** integer.

**Example 1:**

**Input:** root = [1,0,1,0,1,0,1]

**Output:** 22

**Explanation: **(100) + (101) + (110) + (111) = 4 + 5 + 6 + 7 = 22

**Example 2:**

**Input:** root = [0]

**Output:** 0

**Example 3:**

**Input:** root = [1]

**Output:** 1

**Example 4:**

**Input:** root = [1,1]

**Output:** 3

**Constraints:**

- The number of nodes in the tree is in the range
`[1, 1000]`

. `Node.val`

is`0`

or`1`

.

Solution: