Python3 Program for Minimum rotations required to get the same string

Given a string, we need to find the minimum number of rotations required to get the same string.
Examples:

Input : s = "geeks"
Output : 5

Input : s = "aaaa"
Output : 1

Method 1: The idea is based on below post.
A Program to check if strings are rotations of each other or not
Step 1 : Initialize result = 0 (Here result is count of rotations)
Step 2 : Take a temporary string equals to original string concatenated with itself.
Step 3 : Now take the substring of temporary string of size same as original string starting from second character (or index 1).
Step 4 : Increase the count.
Step 5 : Check whether the substring becomes equal to original string. If yes, then break the loop. Else go to step 2 and repeat it from the next index.

Python3

# Python 3 program to determine minimum
# number of rotations required to yield
# same string.
 
# Returns count of rotations to get the
# same string back.
def findRotations(str):
     
    # tmp is the concatenated string.
    tmp = str + str
    n = len(str)
 
    for i in range(1, n + 1):
         
        # substring from i index of
        # original string size.
        substring = tmp[i: i+n]
 
        # if substring matches with
        # original string then we will
        # come out of the loop.
        if (str == substring):
            return i
    return n
 
# Driver code
if __name__ == '__main__':
 
    str = "abc"
    print(findRotations(str))
 
# This code is contributed
# by 29AjayKumar.

Output

Time Complexity: O(n²)
Auxiliary Space: O(n). We are using a temporary string of size n for the concatenated string.

Alternate Implementation in Python :

Python3

# Python 3 program to determine minimum
# number of rotations required to yield
# same string.
  
# input
string = 'aaaa'
check = ''
  
for r in range(1, len(string)+1):
  # checking the input after each rotation
  check = string[r:] + string[:r]
    
  # following if statement checks if input is
  # equals to check , if yes it will print r and
  # break out of the loop
  if check == string:
    print(r)
    break
  
# This code is contributed
# by nagasowmyanarayanan.