@array[$_,-$_-1]=@array[-$_-1,$_] for 0..@array/2;
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@array[$_,-$_-1]=@array[-$_-1,$_] for 0..$#array/2;
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I must have been halucinating when I tested it.

But frankly I stand by my too complex comment regardless.

Yves / DeMerphq
---
Software Engineering is Programming when you can't. -- E. W. Dijkstra (RIP)

Fencepost error. I think you mean:

@array[$_,-$_-1]=@array[-$_-1,$_] for 0..$#array/2;
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The middle pair was swapped twice to no effect for even sized arrays, the middle element swapped with itself for odd.

After Compline,
Zaxo

I actually did #2 the way I did to avoid a fencepost error. And it's proveably correct.

And think of the maintenance programmer. I'd not want to maintain your code.

-- Randal L. Schwartz, Perl hacker

Busted.

Oh well.

I guess I didn't get the job.

Yves / DeMerphq
---
Software Engineering is Programming when you can't. -- E. W. Dijkstra (RIP)

Why not go for truly ugly? ;-)

@array[0..$#array] = @array[map{-$_}(1..@array)];
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---

You have moved into a dark place.
It is pitch black. You are likely to be eaten by a grue.

I'm not sure if treating an interview question like a golf challenge is such a good idea. Well... this guy was good, but this other guy did it in just 14 characters. Not gonna happen. ;-)

()-()
 \"/
  `                                                     

I like merlyn's answer because it's readable, even by people who are not hardcore perl programmers. It's not tricky, but it doesn't need to be.

Actually I disagree quite strongly. Its readable by people with a C background (ie who are used to the while() loops being disguised as for() loops) but to people who come from other backgrounds (such as Pascal) I think the above would cause some palpatations on first reading.

Yves / DeMerphq
---
Software Engineering is Programming when you can't. -- E. W. Dijkstra (RIP)

In Perl6, will ~= between two lists give their intersection in list context?

The runtime scales with the product of the sizes of the two arrays.

    my %b_hash = map { $_ => 1 } @b_array;
    my @new_array = grep $b_hash{$_}, @a_array;
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I'd do something like:

    my %b_hash;
       $b_hash {$_} ++ for @b_array;
    my @c_array = map {($_) x ($b_hash {$_} || 0)} @a_array;
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Abigail

while( @sort_a and @sort_b ){
  if( $sort_a[0] < $sort_b[0]){ shift(@sort_a); }
  elsif( $sort_a[0] > $sort_b[0]{ shift(@sort_b); }
  else{ 
   push @new_array, $sort_a[0];
   shift(@sort_a);
   shift(@sort_b);
  }
}
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