Re: randomly generating A-Za-z

Hi princepawn,

Here's my solution. I'm sure it's not as efficient as some of the others, but its mine, and I like it.:-)

sub letter{
return rand(2)%2 ? chr rand(26)+65 : chr rand(26)+97;
}
[download]

Fortunately chr() rounds down the random value, saving a couple of int() calls.
I hope this is correct.
cheers

thinker

Comment on Re: randomly generating A-Za-z Download Code

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Re: Re: randomly generating A-Za-z by belden (Friar) on Oct 13, 2001 at 00:32 UTC
Hi thinker I'm sure it's not as efficient as some of the others, but its mine, and I like it.:-) Looking back up the thread, I see plenty of hyperefficient solutions to this. Well, here's my shot at the least efficient solution... apologies to princepawn who probably isn't aided in the least by this post `sub fisher_yates() { for(my $i = @_; --$i) { my $j = int rand ($i+1); next if $j == $i; @_[$i,$j] = @_[$j,$i]; } return @_; } sub letter() { for(@_) { my $k = int(rand 52) - 1; return chr $_[$k] if($_[$k] eq $_); } &letter; } # &letter isn't completely random... # print(&letter(65..90,97..122),"\n"); # ...so use Perl Cookbook's Fisher- # Yate Shuffle to randomize the list print(&letter(&fisher_yates(65..90,97..122),"\n");` [download] blyman Update: Running above code several times has confirmed my initial suspicion: &letter() as written is more likely to return an 'A' than a 'z'. Fixed this by adding a Fisher-Yates shuffle; this helps fulfill my original goal of writing the least-efficient algorithm for returning a random letter...	[reply] [d/l]

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Re: Re: randomly generating A-Za-z
by belden (Friar) on Oct 13, 2001 at 00:32 UTC

thinker

I'm sure it's not as efficient as some of the others,
but its mine, and I like it.:-)

Looking back up the thread, I see plenty of hyperefficient
solutions to this. Well, here's my shot at the least efficient
solution... apologies to princepawn who probably isn't aided
in the least by this post

sub fisher_yates()
{
  for(my $i = @_; --$i)
  {
    my $j = int rand ($i+1);
    next if $j == $i;
    @_[$i,$j] = @_[$j,$i];
  }
  return @_;
}


sub letter()
{
  for(@_)
  {
    my $k = int(rand 52) - 1;
    return chr $_[$k] if($_[$k] eq $_);
  }
  &letter;
}

# &letter isn't completely random...
# print(&letter(65..90,97..122),"\n");

# ...so use Perl Cookbook's Fisher-
# Yate Shuffle to randomize the list
print(&letter(&fisher_yates(65..90,97..122),"\n");
[download]

blyman

Update: Running above code several times has
confirmed my initial suspicion: &letter() as written is
more likely to return an 'A' than a 'z'. Fixed this by adding
a Fisher-Yates shuffle; this helps fulfill my original goal
of writing the least-efficient algorithm for returning a
random letter...

[reply]
[d/l]