Tutorialspoint
Problem
Solution
Submissions
Back

Check if Two Strings are Rotations of Each Other

Certification: Intermediate Level Accuracy: 83.33% Submissions: 6 Points: 5

Write a Python function to check if two strings are rotations of each other.

Example 1
    
  
  • Input: string1 = "abcd", string2 = "cdab"
    • 
  
  • Output: True
    • 
  
  • Explanation: 
      
    
    • Step 1: Check if both strings have the same length. "abcd" and "cdab" both have length 4.
      • 
    
    • Step 2: Concatenate string1 with itself: "abcd" + "abcd" = "abcdabcd".
      • 
    
    • Step 3: Check if string2 is a substring of the concatenated string: "cdab" is a substring of "abcdabcd".
      • 
    
    • Step 4: Since "cdab" is a substring of "abcdabcd", return True.
      • 
    
    • Step 5: This confirms that "cdab" is a rotation of "abcd".
      • 
  
    •
Example 2
    
  
  • Input: string1 = "hello", string2 = "world"
    • 
  
  • Output: False
    • 
  
  • Explanation: 
      
    
    • Step 1: Check if both strings have the same length. "hello" and "world" both have length 5.
      • 
    
    • Step 2: Concatenate string1 with itself: "hello" + "hello" = "hellohello".
      • 
    
    • Step 3: Check if string2 is a substring of the concatenated string: "world" is not a substring of "hellohello".
      • 
    
    • Step 4: Since "world" is not a substring of "hellohello", return False.
      • 
    
    • Step 5: This confirms that "world" is not a rotation of "hello".
      • 
  
    •
Constraints
    
  
  • 1 <= len(string1), len(string2) <= 1000
    • 
  
  • Time Complexity: O(n) where n is the length of the strings
    • 
  
  • Space Complexity: O(n)
    •
StringsKPMGSnowflake
Editorial

Login to view the detailed solution and explanation for this problem.

My Submissions
All Solutions
Refresh
Lang Status Date Code
You do not have any submissions for this problem.
Refresh
User Lang Status Date Code
No submissions found.

Please Login to continue
Solve Problems

 
 
 
Output Window
Clear All Apply Filters

Trending

Others

SIGN IN

Don't have an account? Register

Hint
Solution

Solution Hints

    
  
  • Concatenate the first string with itself and check if the second string is a substring of the concatenated string.
    • 
  
  • Handle edge cases where the lengths of the two strings are different.
    •

Steps to solve by this approach:

 Step 1: Check if both strings have equal length (requirement for rotation)
 
 Step 2: Concatenate str1 with itself to create a temporary string (str1+str1)
 
 Step 3: Check if str2 is a substring of the concatenated string
 
 Step 4: If str2 exists within the concatenated string, strings are rotations
 
 Step 5: Return True if they are rotations, False otherwise
 
 Step 6: This works because concatenation contains all possible rotations
 
 Step 7: Example: "abcd" and "cdab" are rotations since "cdab" is in "abcdabcd"

Submitted Code :