Interview question: Check if one string is a rotation of other string [closed]
First make sure s1 and s2 are of the same length. Then check to see if s2 is a substring of s1 concatenated with s1:
algorithm checkRotation(string s1, string s2) if( len(s1) != len(s2)) return false if( substring(s2,concat(s1,s1)) return true return falseendIn Java:
boolean isRotation(String s1,String s2) { return (s1.length() == s2.length()) && ((s1+s1).indexOf(s2) != -1);}