Given a string
s, check if it can be constructed by taking a substring of it and appending multiple copies of the substring together.
Input: s = "abab" Output: true Explanation: It is the substring "ab" twice.
Input: s = "aba" Output: false
Input: s = "abcabcabcabc" Output: true Explanation: It is the substring "abc" four times or the substring "abcabc" twice.
1 <= s.length <= 104
sconsists of lowercase English letters.