0459. Repeated Substring Pattern

https://leetcode.com/problems/repeated-substring-pattern

Description

Given a string s, check if it can be constructed by taking a substring of it and appending multiple copies of the substring together.

Example 1:

**Input:** s = "abab"
**Output:** true
**Explanation:** It is the substring "ab" twice.

Example 2:

**Input:** s = "aba"
**Output:** false

Example 3:

**Input:** s = "abcabcabcabc"
**Output:** true
**Explanation:** It is the substring "abc" four times or the substring "abcabc" twice.

Constraints:

• 1 <= s.length <= 104

• s consists of lowercase English letters.

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