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Check if Two Strings are Rotations of Each Other

Certification: Intermediate Level Accuracy: 50% Submissions: 22 Points: 5

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

Example 1
    
  
  • Input: string1 = "abcd", string2 = "cdab"
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  • Output: True
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  • 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".
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    • Step 4: Since "cdab" is a substring of "abcdabcd", return True.
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    • 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".
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    • 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
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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 :