Linux/Unix 中的冒泡排序 shell 脚本

Question

I am trying to perform bubble sort is Unix shell script. Why is my code not working?

a=(10 8 20 25 12)

for ((i=0;i<5;i++))
do
 for((j=0;j<5;j++))
 do
if ((${a[j]} > ${a[$((j+1))]}))
then
  v=${a[$j]}
  a[$j]=${a[$((j+1))]}
  a[$((j+1))]=$v
    fi
 done
done
    echo ${a[*]}
    echo "end..."

Answer 1

I guess this is homework. therefore I don't give codes, just point out the errors in your codes:

for((j=0;j<5;j++)) then read a[j+1] , here would be problem because when j=4 , j+1 doesn't exist

fix that, your program will sort.

Answer 2

Try this:

echo "Enter size of array";
read  n; #get the size of array from user.
echo "Enter the array";
read -a arr;  #get the array form user eg: 2 3 4 5 6
echo "Orignal array is: ${arr[*]}"; #print orignal array

flag=1;
for (( i = 0; i < $n-1; i++ ))
do
    flag=0;
    for ((j = 0; j < $n-1-$i; j++ ))
    do
        if [[ ${arr[$j]} -gt ${arr[$j+1]} ]]
        then
            temp=${arr[$j]};
            arr[$j]=${arr[$j+1]};
            arr[$j+1]=$temp;
            flag=1;
        fi
    done

    if [[ $flag -eq 0 ]]; then
        break;
    fi
      
done
echo "Final sorted Array is ${arr[*]}";