1012. Numbers With Repeated Digits

https://leetcode.com/problems/numbers-with-repeated-digits

Description

Given an integer n, return the number of positive integers in the range [1, n] that have at least one repeated digit.

Example 1:

**Input:** n = 20
**Output:** 1
**Explanation:** The only positive number (<= 20) with at least 1 repeated digit is 11.

Example 2:

**Input:** n = 100
**Output:** 10
**Explanation:** The positive numbers (<= 100) with atleast 1 repeated digit are 11, 22, 33, 44, 55, 66, 77, 88, 99, and 100.

Example 3:

**Input:** n = 1000
**Output:** 262

Constraints:

• 1 <= n <= 109

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