linux bash shell實現對數組快速排序（升序）

2011年12月19日，參考網上用C語言實現的快速排序，經過一番修改後，用shell（我的測試環境爲centos5的bash-v3.x）實現了相同功能：對數組進行升序排序。

注：如果代碼框裏的代碼複製出來後顯示異常，就麻煩下載附件chris.zip（已將chris-qsort.sh和chris-algo.sh壓縮打包爲chris.zip）

1. shell函數形式（已將其放在附件裏，文件名爲：chris-qsort.sh。由於沒法上傳.sh腳本，故壓縮打包了一下，文件名爲：chris.zip）：

Quick_Sort(){
    #Sort Numeric-array in ASC order, using normal Quick-Sort algorithm.
    #C code: http://www.cnblogs.com/skyaspnet/archive/2010/11/03/1868298.html
    #Usage: Quick_Sort lowest_index highest_index array_name
    #e.g.,  Quick_Sort 0 9 array1
    #e.g.,  Quick_Sort 1 3 array2

    local array=${3}
    eval local pivot=\$\{${array}[${1}]\}
    local low=${1}
    local high=${2}

    [ ${1} -ge ${2} ] && return

    while [ ${low} -lt ${high} ]; do
        while [ ${low} -lt ${high} -a ${pivot} -le $(eval echo \$\{${array}[${high}]\}) ]; do
            let high--
        done
        if [ ${pivot} -gt $(eval echo \$\{${array}[${high}]\}) ]; then
            eval ${array}[${low}]=\$\{${array}[${high}]\}
            eval ${array}[${high}]=${pivot}
            let low++
        fi

        while [ ${low} -lt ${high} -a ${pivot} -ge $(eval echo \$\{${array}[${low}]\}) ]; do
            let low++
        done
        if [ ${pivot} -lt $(eval echo \$\{${array}[${low}]\}) ]; then
            eval ${array}[${high}]=\$\{${array}[${low}]\}
            eval ${array}[${low}]=${pivot}
            let high--
        fi
    done

    #Execute the Quick_Sort function recursively
    Quick_Sort ${1} $[${low}-1] ${array}
    Quick_Sort $[${low}+1] ${2} ${array}

    unset array pivot low high
}

 

 

2. shell腳本形式，進行簡單測試（已將其放在附件裏，文件名爲chris-algo.sh。由於沒法上傳.sh腳本，故壓縮打包了一下，文件名爲：chris.zip）。

#!/bin/bash
##################################################
## Author     :  Chris
## Create Date:  2011-12-19
## Modify Date:  2012-05-14
## Realize common algorithms in bash-v3.x
## Note: Every function represents an algorithm.
##################################################

#Normal Quick-Sort algorithm
Quick_Sort(){
    #Sort Numeric-array in ASC order, using normal Quick-Sort algorithm.
    #C code: http://www.cnblogs.com/skyaspnet/archive/2010/11/03/1868298.html
    #Usage: Quick_Sort lowest_index highest_index array_name
    #e.g.,  Quick_Sort 0 9 array1
    #e.g.,  Quick_Sort 1 3 array2

    local array=${3}
    eval local pivot=\$\{${array}[${1}]\}
    local low=${1}
    local high=${2}

    [ ${1} -ge ${2} ] && return

    while [ ${low} -lt ${high} ]; do
        while [ ${low} -lt ${high} -a ${pivot} -le $(eval echo \$\{${array}[${high}]\}) ]; do
            let high--
        done
        if [ ${pivot} -gt $(eval echo \$\{${array}[${high}]\}) ]; then
            eval ${array}[${low}]=\$\{${array}[${high}]\}
            eval ${array}[${high}]=${pivot}
            let low++
        fi

        while [ ${low} -lt ${high} -a ${pivot} -ge $(eval echo \$\{${array}[${low}]\}) ]; do
            let low++
        done
        if [ ${pivot} -lt $(eval echo \$\{${array}[${low}]\}) ]; then
            eval ${array}[${high}]=\$\{${array}[${low}]\}
            eval ${array}[${low}]=${pivot}
            let high--
        fi
    done

    #Execute the Quick_Sort function recursively
    Quick_Sort ${1} $[${low}-1] ${array}
    Quick_Sort $[${low}+1] ${2} ${array}

    unset array pivot low high
}

main(){
    read -ep "Input Numeric: " numeric
    size=$(echo ${numeric} | awk '{print NF}')

    #Define array
    t_array=(${numeric})

    #Output the original array
    for((i=0;i<${size};i++)); do
        printf "%d " ${t_array[${i}]}
    done
    printf "\n"

    #Using Quick_Sort function to sort t_array
    size_1=$[${size} - 1]
    Quick_Sort 0 ${size_1} t_array

    #Output the sorted array
    for((i=0;i<${size};i++)); do
        printf "%d " ${t_array[${i}]}
    done
    printf "\n"
}

main

 輸出如下：

[root@localhost algorithms]# ./chris-algo.sh
49 38 65 97 76 13 27 9 2 1
1 2 9 13 27 38 49 65 76 97

 

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