459. Repeated Substring Pattern

//Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may assume the given string consists of lowercase English letters only and its length will not exceed 10000.
//
//Example 1:
//Input: "abab"
//
//Output: True
//
//Explanation: It's the substring "ab" twice.
//Example 2:
//Input: "aba"
//
//Output: False
//Example 3:
//Input: "abcabcabcabc"
//
//Output: True
//
//Explanation: It's the substring "abc" four times. (And the substring "abcabc" twice.)

public class RSPattern459 {
	public static boolean repeatedSubstringPattern(String s) {
		int len = s.length();
		
		for(int l = 1; l < len/2 + 1; l++){
			boolean isMatch = false;
			for(int i = 1; i < len/l; i++){
				if(s.substring(0, l).equals(s.substring(i*l,(i+1)*l))){
					isMatch = true;
				}
				else{
					isMatch = false;
					break;
				}
			}
			if(isMatch && len%l == 0){
				return true;
			}
		}
		return false;
	    }
	
	public static void main(String[] args){
		System.out.println(repeatedSubstringPattern("bb"));
	}
}