Question

write a bash program to do merge sort. in that program make sure, you read the array of size 20 using a function, and another function for output of the array and use separate functions to do merge sort

Answer 1

Hello!

Below is your code

run the script and enter your 20 numbers in next line

-------------------------------
#!/bin/bash

input(){
read -a a
}

merge() {
local first=2
local second=$(( $1 + 2 ))
for i in ${@:2}
do
if [[ $first -eq $(( $1 + 2 )) ]]
then
echo ${@:$second:1} ; ((second += 1))
else
if [[ $second -eq $(( ${#@} + 1 )) ]]
then
echo ${@:$first:1} ; ((first += 1))
else
if [[ ${@:$first:1} -lt ${@:$second:1} ]]
then
echo ${@:$first:1} ; ((first += 1))
else
echo ${@:$second:1} ; ((second += 1))
fi
fi
fi
done
}

mergesort() {
if [[ $1 -ge 2 ]]
then
local med=$(( $1 / 2 ))
local first=( $(mergesort $med ${@:2:$med}) )
local second=( $(mergesort $(( $1 - $med )) ${@:$(( $med + 2 )):$(( $1 - $med ))}) )
echo $(merge $med ${first[@]} ${second[@]})
else
echo $2
fi
}

output(){
echo ${a[@]} ; echo $(mergesort 20 ${a[@]})
}

input

output
-----------------------------------

Output:

Hoping it will help!