#1015

Smallest Integer Divisible by K

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Description

Given a positive integer k, find the length of the smallest positive integer n consisting entirely of the digit 1 (a repunit) that is divisible by k.

Return the length of n. If no such n exists, 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.

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