30 March 2012

Shell Script for Bubble Sort

By Sandeep 12:33 AM , , 9 comments

Q. How do I write Bubble sort in Bash


Ans:

#!/bin/bash
echo "enter maximum number"
read n
# taking input from user
echo "enter Numbers in array:"
for (( i = 0; i < $n; i++ ))
do
read nos[$i]
done
#printing the number before sorting
echo "Numbers in an array are:"
for (( i = 0; i < $n; i++ ))
do
echo ${nos[$i]}
done
# Now do the Sorting of numbers
for (( i = 0; i < $n ; i++ ))
do
for (( j = $i; j < $n; j++ ))
do
if [ ${nos[$i]} -gt ${nos[$j]}  ]; then
t=${nos[$i]}
nos[$i]=${nos[$j]}
nos[$j]=$t
fi
done
done
# Printing the sorted number
echo -e "\nSorted Numbers "
for (( i=0; i < $n; i++ ))
do
echo ${nos[$i]}
done

Output



Enjoy :)


If You Liked This Post Please Take a Time To Share This Post

You May Also Like...

9 comments:

  1. AnonymousJuly 23, 2015 at 7:03 PM

    You need to declare the array: declare -a nos to make the script work.

    ReplyDelete
  2. AnonymousMay 6, 2016 at 10:24 AM

    nthonnaadeeyyyy ithu.... poy pani panikkedaaaaa ********
    for(p=1;p<=n-1;p++) // Loop for Pass
    {

    for(j=1;j<=n-1;j++)
    {
    if(a[j]>a[j+1])
    {
    temp=a[j]; // Interchange Values
    a[j]=a[j+1];
    a[j+1]=temp;
    }
    }

    ReplyDelete
  3. UnknownJuly 22, 2017 at 10:32 AM

    Thank you

    ReplyDelete
  4. AnonymousOctober 12, 2017 at 8:38 AM

    this code is showing an error of " unary operator expected"

    ReplyDelete
  5. AnonymousMarch 15, 2018 at 10:23 AM

    It was hard for me to imagine how nested loops works.
    Let run this script, may help for newbees like me.

    #!/bin/bash
    clear
    read -p "Give a number > 1 but <= 4: " n
    echo
    # I nested 3 for loop-s
    for ((i=1;i<=$n;i++))
    do
    echo "------------- $i. i loop ->"

    # ------------------->>
    for ((j=$i;j<=$n;j++))
    do
    tput setaf 1;
    echo " --------- $i/$j. j loop"
    tput sgr0

    # ------------------->>
    for ((f=$j;f<=$n;f++))
    do
    tput setaf 2;
    echo " ----$i/$j/$f. f loop"
    tput sgr0
    done
    # -----------------------------------------------
    done
    # -----------------------------------------------
    echo "------------- $i. i loop-ENDing >|"
    # read x # uncomment if you whant to see on the flow. Just hit
    echo
    done

    ReplyDelete
  6. baligekoFebruary 19, 2019 at 6:09 AM

    The initial code given above is NOT a bubble sort.
    I sorts in the end,
    but if you echo the array in every step,
    it is doing something bizarre.

    ReplyDelete
  7. baligekoFebruary 19, 2019 at 7:28 AM

    # This is indeed a bubble sort.
    #!/bin/bash
    #echo "enter maximum number"
    #read n
    let n=9
    # taking input from user
    #echo "enter Numbers in array:"
    #for (( i = 0; i < $n; i++ ))
    #do
    #read nos[$i]
    #done
    nos=(544 798 132 555 888 444 999 585 111)
    #printing the number before sorting
    echo "Numbers in an array are:"
    #for (( i = 0; i < $n; i++ ))
    # do
    # echo -ne ${nos[$i]} " "
    # done
    #echo
    #echo

    # Now do the Sorting of numbers
    # To save computation, you need a flag !!!
    for (( i = 0; i < $n ; i++ ))
    do
    # Start at first entry.
    for (( j = 0 ; j < $n-1 ; j++ ))
    do

    # Debug.
    echo -ne I${i}J${j} " "
    for (( x=0; x < $n; x++ ))
    do
    echo -ne ${nos[$x]} " "
    done #x

    # Maybe swap.
    if [ ${nos[$j]} -gt ${nos[$j+1]} ]; then
    echo -ne "( " ${nos[$j]} " <-> " ${nos[$j+1]} " )"
    t=${nos[$j]} #Save as temp.
    nos[$j]=${nos[$j+1]}
    nos[$j+1]=$t
    fi



    # Newline.
    echo

    done #j



    #echo
    done #i

    # Debug.
    echo -ne I${i}J${j} " "
    for (( x=0; x < $n; x++ ))
    do
    echo -ne ${nos[$x]} " "
    done #x
    echo

    ReplyDelete
  8. baligekoFebruary 19, 2019 at 7:29 AM

    It is unfortunate that leading space indentation is removed !!!

    ReplyDelete