#!/usr/bin/env perl

use strict;
use warnings;
use feature qw (say);

my @n = ( 1 .. 50 );

# ad libitum:
# open( my $urandom, "</dev/urandom" ) or die $!;
# read( $urandom, $_, 4 );
# close $urandom;

# srand( unpack( "L", $_ ) );

# for ( my $i = @n ; --$i ; ) {
#     my $j = int( rand( $i + 1 ) );
#     next if $i == $j;
#     @n[ $i, $j ] = @n[ $j, $i ];
# }

say scalar map { 1 .. $_ }
  map { splice( @n, int( rand(@n) ), 1 ) } ( 1 .. 5 )
  for 1 .. 5;

__END__