To determine whether string is rotated or not in java (without using loops)

By Sameer

In this tutorial, we will learn how to determine whether the string is one of its rotation of the given string in Java.

For example, if the given string is ABCD then its circular rotations are BCDA, CDBA, DABC, ABCD. If the input string is present in either of the obtained rotations the output should print true otherwise should print false.

determine whether string is rotated or not in java

1 <= N <= 100000

1<= M <= 100000

Sample Input:

ABCD

BCDA

Sample Output:

true

Explanation: BCDA is one its rotation of ABCD.

Without using loops we can solve this problem using indexOf() method. First, we concatenate the given string itself and with indexOf() method we can identify at which index the available string is present. If it is true then it is one of its rotations then it is false.

String indexOf(String str): This method returns the index within this string of the first occurrence of the specified substring. If it does not occur as a substring, -1 is returned.

import java.util.*;
class codespeedy
{
  public static void main (String args[])
  {
    Scanner sc=new Scanner(System.in);
    String str1="hello";
    String str2="llohe";
    //Form a new string by concatenating the given string itself
    String str=str1+str1; //hellohello
    System.out.println("Output:");
    if(str1.length()==str2.length() && str.indexOf(str2)!=-1)
                {
      System.out.println("true");
    }
    else {
      System.out.println("false");
    }
  }
}

Output:
true

We hope this tutorial helped you to understand how to solve the given problem statement without using loops.

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