1015. Smallest Integer Divisible by K

https://leetcode.com/problems/smallest-integer-divisible-by-k

Description

Given a positive integer k, you need to find the length of the smallest positive integer n such that n is divisible by k, and n only contains the digit 1.

Return the length of n. If there is no such n, return -1.

Note: n may not fit in a 64-bit signed integer.

Example 1:

**Input:** k = 1
**Output:** 1
**Explanation:** The smallest answer is n = 1, which has length 1.

Example 2:

**Input:** k = 2
**Output:** -1
**Explanation:** There is no such positive integer n divisible by 2.

Example 3:

**Input:** k = 3
**Output:** 3
**Explanation:** The smallest answer is n = 111, which has length 3.

Constraints:

• 1 <= k <= 105

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