Re: (OT) Interview questions -- your response?

[tadman]

Here's my take on Q1, which isn't entirely original, but is self-contained:

my @c = do { my %tmp = map { $_ => 1 } @a; grep {$tmp{$_}} @b };

Here's my take on Q2 which ended up the same as others:

for (1..@foo/2) { @foo[$_-1,-$_] = @foo[-$_,$_-1]; }

The first thing that came to mind was:

@foo = map { pop(@foo) } 1..@foo;

But that's not precisely an in-place version, even though you could argue that the temporary "array" only holds things that have been removed from @foo.

[demerphq]

If your going to use $_ anyway you might as well use the more efficient modifier form (no scope handling overhead).

@foo[$_-1,-$_] = @foo[-$_,$_-1] for (1..@foo/2);

BTW: I think this is probably the best implementation (starting at one instead of zero) of all that have been present along this line (especially including my embarrasing fencepost error version) so ++ to you.

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