shell 冒泡排序

#! /bin/bash

set -x

a=( 2 4 3 6 3 1 5 9 7 )

bubble_sort()
{
    n=${#a[@]}

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

echo ${a[@]}
bubble_sort
echo ${a[@]}