powershell -noprofile -executionpolicy bypass "1..100|%%{((97..122),(65..90),(48..57)|%%{[char[]]$_}|Get-Random -Count 4) -join ''}" > rnd.txt
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function powerset(x, y) {
    if (length(x) > 3 || y > length($0)) {
        print x
        return
    }
    powerset(x, y + 1)
    powerset(x substr($0, y, 1), y + 1)
}
{
    powerset("", 1)
}
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/*&cls&echo off&cd /d "%~dp0"
set "length=3"
set "count=100"
cscript -nologo -e:jscript "%~f0" "%length%" "%count%" > "out.txt"
pause
exit
*/
var len=WSH.Arguments(0).split(/[-,~]/),count=Number(WSH.Arguments(1));
var charlist=[
    ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"],
    ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"],
    ["0","1","2","3","4","5","6","7","8","9"]
];

var r1=Number(len[0]);
function getrandom(){
    if(len.length==2){r1=Math.floor(Math.random()*(Number(len[1])-Number(len[0]))+Number(len[0]));}
    var s=[];
    for(var i=1;i<=r1;i++){
        var r2=Math.floor(Math.random()*charlist.length);
        var r3=Math.floor(Math.random()*charlist[r2].length);
        s.push(charlist[r2][r3]);
    }
    return s.join("");
}

var dic={},n=0;
for(;;){
    var rs=getrandom();
    if(dic[rs]==undefined){
        WSH.echo(rs);
        n=n+1;dic[rs]='';
        if(n>=count){break;}
    }
}
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import itertools
s = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
with open(r'a.txt','w') as f:
    for i in range(1, 5):
        for j in itertools.permutations(s, i):
            f.write(''.join(j)+'\n')
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with recursive c as (
select x, 1 n from t
union all
select c.x || t.x, c.n + 1
from c join t
where c.n < 4 and c.x not like '%' || t.x || '%'
)
select x from c;
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@echo off
set str1=0 1 2 3 4 5 6 7 8 9
set str2=a b c d e f g h i j k l m n o p q r s t u v w x y z
set str3=A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
set str=%str1% %str2% %str3%
(for %%i in (%str%) do (
    echo,%%i
    for %%j in (%str%) do (
        echo,%%i%%j
        for %%k in (%str%) do (
            echo,%%i%%j%%k
            for %%l in (%str%) do (
                echo,%%i%%j%%k%%l
            )
        )
    )
))>1.txt
pause
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<# :
cls&echo off&cd /d "%~dp0"&set "current=%cd%"
path %SYSTEMROOT%\System32\WindowsPowerShell\v1.0;%path%
echo;waiting...
powershell -NoProfile -ExecutionPolicy bypass "Get-Content -literal \"%~f0\"|Out-String|Invoke-Expression"
echo;done
pause
exit
#>
$current=($env:current).trimend('\');
$outfile=$current+'\out.txt';
$fs=New-Object System.IO.FileStream($outfile, [System.IO.FileMode]::Create);
$sw=New-Object System.IO.StreamWriter($fs, [Text.Encoding]::GetEncoding('GB2312'));
$arr=New-Object -TypeName System.Collections.ArrayList;
$charlist=@(97..122)+@(65..90)+@(48..57);
for($i=1;$i -le 4;$i++){
    $brr=New-Object -TypeName System.Collections.ArrayList;
    if($arr.count -eq 0){
        for($j=0;$j -lt $charlist.length;$j++){
            $c=([char]$charlist[$j]).toString();
            $sw.WriteLine($c);
            [void]$brr.add($c);
        }
    }else{
        for($j=0;$j -lt $arr.count;$j++){
            for($k=0;$k -lt $charlist.length;$k++){
                $c=([char]$charlist[$k]).toString();
                $s=$arr[$j]+$c
                $sw.WriteLine($s);
                [void]$brr.add($s);
            }
        }
    }
    $sw.Flush();
    $arr=$brr;
}
$sw.Close();
$fs.Close();
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