public class Solution
extends Object
2376 - Count Special Integers\.
Hard
We call a positive integer **special** if all of its digits are **distinct**.
Given a **positive** integer `n`, return _the number of special integers that belong to the interval_ `[1, n]`.
**Example 1:**
**Input:** n = 20
**Output:** 19
**Explanation:** All the integers from 1 to 20, except 11, are special. Thus, there are 19 special integers.
**Example 2:**
**Input:** n = 5
**Output:** 5
**Explanation:** All the integers from 1 to 5 are special.
**Example 3:**
**Input:** n = 135
**Output:** 110
**Explanation:** There are 110 integers from 1 to 135 that are special.
Some of the integers that are not special are: 22, 114, and 131.
**Constraints:**
* 1 <= n <= 2 * 109