Your first is better, but doesn't work as written. Try something like:

my $i = 0;
my %fullHash = map { ($i++, $_) } @rows;
# Delete your stuff here
my @keeplist = map { $fullhash{$_} } sort { $a <=> $b } keys %fullHash
+;
[download]

The problem was that you were reconstituting the array in the random order of the hash. Hashes don't preserve order, so you may need to sort if you're going from hash => array.

Update: Modified the sort from ASCIIbetically to numerically. Whoops! :-)

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