Check whether two strings are rotational equal or not

Check whether two strings are rotational equal or not 

(rotations of each other or not)

Given a string s1 and a string s2, check whether s2 is a rotation of s1

s1 = WXYZ and s2 = YZWX, return true

s1 = WXYZ, and s2 = XWYZ, return false

Solution # 1

public static boolean checkRotational(String str1, String str2) {

     int length = str1.length();

     // Check if both strings are of equal size

     // Check if both strings are exactly equal

     if (length != str2.length()) {

        return false;

     } else if (str1.equals(str2)) {

        return true;

     }

     // Manipulate first string and match with other one

     // Take one char of string and rest of string, Join s2+s1

     for(int i=1; i<length; i++) {

        String s1 = str1.substring(0,1);

        String s2 = str1.substring(1, length);

        str1 = s2+s1;

        if(str2.equals(str1)) {

           return true;

        }

      }

     

     return false;

}

Best Solution # 2

static boolean checkRotational(String str1, String str2) {

     // Add string 1 two times into str1

     str1 = str1+str1;

     // Check if str1 contains other string

     if(str1.contains(str2)) {

         return true;

     } else {

         return false;

     }

}