Here are a few title options, incorporating the question-answer format and focusing on the key takeaways: **Option 1 (Direct & Concise):** * **Is String s1 a Rotation of String s2? A Simple Solu

Rotation Verification with String Concatenation

In software development interviews, candidates often face complex questions that test their problem-solving skills. One such challenge is determining if one string is a rotated version of another.

Consider the following interview question:

Question:

Given two strings, s1 and s2, how do you determine if s1 is a rotated version of s2?

Example:

• s1 = "stackoverflow"
• Rotated versions: "tackoverflows", "ackoverflowst", "overflowstack"
• Non-rotated version: "stackoverflwo"

Previously, an interviewee proposed a solution that involved finding the rotation point and concatenating split substrings. However, the interviewer requested a simpler approach.

Optimal Solution:

A more efficient solution utilizes string concatenation. It checks if s2 is a substring of s1 concatenated with itself. This ensures that all possible rotations are considered.

Pseudocode:

algorithm checkRotation(string s1, string s2) 
  if( len(s1) != len(s2))
    return false
  if( substring(s2,concat(s1,s1))
    return true
  return false
end

Java Implementation:

<code class="java">boolean isRotation(String s1,String s2) {
    return (s1.length() == s2.length()) &amp;&amp; ((s1+s1).indexOf(s2) != -1);
}</code>

This algorithm offers a straightforward and effective way to determine if a string is a rotation of another, meeting the interviewer's request for a simpler solution.

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