Rotate String – HackerRank Solution

In this post, we will solve Rotate String HackerRank Solution. This problem (Rotate String) is a part of HackerRank Functional Programming series.


Scturtle likes strings very much. He is getting bored today, because he has already completed this week’s task and doesn’t have anything else to do. So he starts left-rotating a string. If the length of the string is n, then he will rotate it n times and note down the result of each rotation on a paper.

For a string S = s1 s2 . . . sn, n rotations are possible. Let’s represent these rotations by r1, r2 . . . rn. Rotating it once will result in string r1 = s2s3 . . . sns1, rotating it again will result in string r2 = s3s4 . . . sns1s2 and so on. Formally, ith rotation will be equal to ri = si+1 . . . sn-1 sn s1 . . . si. Note that rn = S.

Your task is to display all n rotations of string S.

For example, if S = abc then it has 3 rotations. They are r1 = bcar2 = cab and r3 = abc.

Input Format

The first line contains an integer, T, which represents the number of test cases to follow. Then follows T lines, which represent a test case each.
Each test case contains a string, S, which consists of lower case latin characters (‘a‘ – ‘z‘) only.

Output Format

For each test case, print all the rotations, r1 r2 . . . rn, separated by a space.


  • 1 <= T <= 10
  • 1 <= n <= 102
  • S will consist of lower case latin character, [‘a‘ . . . ‘z‘] only.

Sample Input


Sample Output

bca cab abc
bcdea cdeab deabc eabcd abcde
baba abab baba abab
aaa aaa aaa


Test case #1: This case is mentioned in the problem statment.
Test case #2: Rotations of abcde are: bcdea -> cdeab -> deabc -> eabcd -> abcde.
Test case #3: Rotations of abab are: baba -> abab -> baba -> abab.
Test case #4: All three rotations will result into same string.
Test case #5: Only one rotation is possible, and that will result into original string.

Solution – Rotate String – HackerRank Solution


import java.util.Scanner

object Solution {

  def main(args: Array[String]): Unit = {
    val sc = new Scanner(

    val t = sc.nextInt

    (0 until t).foreach(_ => {
      val s = sc.nextLine

      case class Acc(s: String, answer: List[String])
      println((0 until s.length).foldLeft(Acc(s, Nil))((acc, _) => {
        val nextV = acc.s.tail + acc.s.head
        Acc(nextV, nextV :: acc.answer)
      }).answer.reverse.mkString(" "))

Note: This problem (Rotate String) is generated by HackerRank but the solution is provided by CodingBroz. This tutorial is only for Educational and Learning purpose.

Leave a Comment

Your email address will not be published. Required fields are marked *