CareerCup1.8.py

"""
 ============================================================================
 Question        : 1.8 Assume you have a method isSubstring which checks if one word is a substring of another. 
                    Given two strings, s1 and s2, write code to check if s2 is 
                    a rotation of s1 using only one call to isSubstring (e.g.,"waterbottle"is a rotation of"erbottlewat").
 Solution        : Concatenate s1 with s1, check if s2 is a substring of s1 + s1
 Time Complexity : Depend on isSubstring()
 Space Complexity: O(n)
 Gist Link       : https://gist.github.com/habina/33b581c69f59fccfc1a6
 ============================================================================
"""

s1 = "waterbottle"
s2 = "erbottlewat"
s1_plus_s1 = s1 + s1
if(s2 in s1_plus_s1 and len(s1) == len(s2)):
    print("s2 is a rotation of s1")
else:
    print("s2 is not a rotation of s1")