Sounds like course/homework or an interview question ;) See Sorting Arrays Without using SORT function or search for similar discussions.

Just writing plz help me is a bit unspecific. You need to explain more in detail, at which point you got stuck.

Priti24:

This should provide you a couple hints:

$ cat bozosort.pl
#!/usr/bin/perl
use strict;
use warnings;

my @list = (1, 2, 3, 9, 6, 4, 5, 7, 0);

while (@list) {
    my $idx = int rand @list;
    next if grep { $list[$idx] > $_ } @list;
    say splice @list, $idx, 1;
}
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On my machine, this produces:

$ perl bozosort.pl
0
1
2
3
4
5
6
7
9
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You'll want to make appropriate changes to improve performance, use files, etc.

Update: Hung a lantern on it.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

I like stooge sort more. It can be much more efficient: I used functional-programming techniques which means it can be trivially parallelised over many CPUs.

sub stoogesort {
    my (@lst) = @_;

    if ($lst[-1] < $lst[0]) {
        # swap
        @lst[0, -1] = @lst[-1, 0];
    }

    return @lst if (@lst < 3);

    # thirds
    my $zero  = 0;
    my $one   = int(@lst / 3);
    my $two   = int($#lst * 2 / 3);
    my $three = $#lst;

    for my $range (
        [ $zero .. $two   ],
        [ $one  .. $three ],
        [ $zero .. $two   ] ) {
        @lst[ @$range ] = stoogesort( @lst[ @$range ] );
    }

    return @lst;
}

my @list = (1, 2, 3, 9, 6, 4, 5, 7, 0);

print join(" ", stoogesort(@list)), "\n";
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% sort onefile > anotherfile
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Some helpful further reading:

• Inefficient sort algorithms
• Bogosort

Update: use Acme::Sort::Bozo by davido.

Update: A nice visualization

Best regards, Karl

You're in luck. If someone were asking me to sort strings, sort would be my second choice too. My first choice would probably be Unicode::Collate. Wrap your solution around that module, and you've satisfied the requirement of not using sort, while at the same time providing a better solution that sort would have offered in the first place.

I'm aware that this answer probably is of little help to you in your interview; the interviewer probably wants to see you write a sort. But if he's interested in getting the job done well, maybe he will respect the answer. ;)