233\. Number of Digit One

Hard

Given an integer `n`, count _the total number of digit_ `1` _appearing in all non-negative integers less than or equal to_ `n`.

**Example 1:**

**Input:** n = 13

**Output:** 6 

**Example 2:**

**Input:** n = 0

**Output:** 0 

**Constraints:**

*   <code>0 <= n <= 10<sup>9</sup></code>