Write a function that takes two input strings and determines if one is a rotation of the other. For instance, “ProgrammingPraxis” and “PraxisProgramming” are rotations of each other, but “ProgrammingPrasix” is not a rotation of “ProgrammingPraxis” because the last three letters are out of order.
public class Solution {
public static void main(String[] args) {
System.out.println(isRotation("abc", "abc"));
System.out.println(isRotation("abc", "cba"));
}
public static boolean isRotation(String str1, String str2) {
if (str1 == null || str2 == null || str1.length() != str2.length()) return false;
for (int offset = 0; offset < str1.length(); offset++) {
int i = 0;
for (i = 0; i < str2.length(); i++) {
if (str2.charAt(i) != str1.charAt((i + offset) % str2.length())) {
break;
}
}
if (i == str2.length()) {
return true;
}
}
return false;
}
}
boolean isRotation(String s1,String s2) {
if (s1 == null || s2 == null) return false;
return (s1.length() == s2.length()) && ((s1+s1).indexOf(s2) != -1);
}
http://programmingpraxis.com/2012/01/31/string-rotation/
http://stackoverflow.com/questions/2553522/interview-question-check-if-one-string-is-a-rotation-of-other-string