Prefix Compression – HackerRank Solution

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


You are in charge of data transfer between two Data Centers. Each set of data is represented by a pair of strings. Over a period of time you have observed a trend: most of the times both strings share some prefix. You want to utilize this observation to design a data compression algorithm which will be used to reduce amount of data to be transferred.

You are given two strings, x and y, representing the data, you need to find the longest common prefix (p) of the two strings. Then you will send substring px’ and y’, where x’ and y’ are the substring left after stripping p from them.

For example, if x = “abcdefpr” and y = “abcpqr”, then p = “abc”, x’ = “defpr”y’ = “pqr”.

Input Format

The first line contains a single string denoting x.
The second line contains a single string denoting y.


  • x and y will contain only lowercase Latin characters (‘a’-‘z’).
  • 1 <= length(x), length(y) <= 105

Output Format

In first line, print the length of substring p, followed by prefix p. In second line, print the length of substring x’, followed by substring x’. Similarly in third line, print the length of substring y’, followed by substring y’.

Sample Input 0


Sample Output 0

3 abc
5 defpr
3 pqr

Sample Input 1


Sample Output 1

=== codingbroz.com_728x90 (#88864) ===
=== codingbroz.com_728x90 (#88864) ===
3 kit
3 kat

Sample Input 2


Sample Output 2

5 puppy


Sample Case 0:
Already explained above in the problem statement.

Sample Case 1:
 p =“kit”, which is also y. So x’ will be “kat” and y’ will be an empty string.

Sample Case 2:
Because both strings are the same, the prefix will cover both the strings. Thus, x’ and y’ will be empty strings.

Solution – Prefix Compression – HackerRank Solution


import java.util.Scanner

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

    val s0 = sc.nextLine
    val s1 = sc.nextLine


    val prefixLen = { case (c0, c1) => c0 == c1 }.length

    printf(s"$prefixLen ${s0.take(prefixLen)}\n")
    printf(s"${s0.length - prefixLen} ${s0.drop(prefixLen)}\n")
    printf(s"${s1.length - prefixLen} ${s1.drop(prefixLen)}\n")

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

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