HackerRank Concatenate an array with itself problem solution YASH PAL, 31 July 2024 In this HackerRank Concatenate an array with itself problem solution we have 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. Problem solution. arr=($(cat)) printf "${arr[*]} ${arr[*]} ${arr[*]}" Second solution. while read country do countries=("${countries[@]}" $country) done for i in `seq 1 3` do echo -n "${countries[@]} " done Third solution. #! /bin/bash while read line do array[${#array[@]}]=$line done echo "${array[@]} ${array[@]} ${array[@]}" Fourth solution. ARRAY=() while read line; do ARRAY+=($line) done; RESULT=() for i in `seq 0 ${#ARRAY[@]}`; do RESULT+=(${ARRAY[$i]}) done; for i in `seq 0 ${#ARRAY[@]}`; do RESULT+=(${ARRAY[$i]}) done; for i in `seq 0 ${#ARRAY[@]}`; do RESULT+=(${ARRAY[$i]}) done; echo ${RESULT[@]} coding problems linux shell