Concatenate an array with itself – HackerRank Solution

In this post, we will solve Concatenate an array with itself HackerRank Solution. This problem (Concatenate an array with itself) is a part of Linux Shell series.

Task

Given a list of countries, each on a new line, your task is to read them into an array. Then, concatenate the array with itself (twice) – so that you have a total of three repetitions of the original array – and then display the entire concatenated array, with a space between each of the countries’ names.

Input Format

A list of country names. The only characters present in the country names will be upper or lower case characters and hyphens.

Output Format

Display the entire concatenated array, with a space between each of them.

Sample Input

Namibia
Nauru
Nepal
Netherlands
NewZealand
Nicaragua
Niger
Nigeria
NorthKorea
Norway

Sample Output

Namibia Nauru Nepal Netherlands NewZealand Nicaragua Niger Nigeria NorthKorea Norway Namibia Nauru Nepal Netherlands NewZealand Nicaragua Niger Nigeria NorthKorea Norway Namibia Nauru Nepal Netherlands NewZealand Nicaragua Niger Nigeria NorthKorea Norway

Explanation

The entire concatenated array has been displayed.

Solution – Concatenate an array with itself – HackerRank Solution

#Given a list of countries, each on a new line, your task is to read them into an array. Then, concatenate the array with itself (twice) - so that you have a total of three repetitions of the original array - and then display the entire concatenated array, with a space between each of the countries' names
arr=($(cat))
arr=("${arr[@]}" "${arr[@]}" "${arr[@]}")
echo ${arr[@]}

Note: This problem (Concatenate an array with itself) is generated by HackerRank but the solution is provided by CodingBroz. This tutorial is only for Educational and Learning purpose.