comment on

This may work as well...

@hugearray = ( ... );
@toremove = ( ... );

# remove from @hugearray elements indexed in @toremove
@hugearray[@toremove] = ("RemoveMe") x @toremove;
push @hugearray, "SentinelFlag";
for (my $_;;) {
  $_ = shift @hugearray;
  last if $_ eq "SentinelFlag";
  next if $_ eq "RemoveMe";
  push @hugearray, $temp;
}
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This works by flagging the elements you want to delete, then using @hugearray as a circular shift register, shift-pushing each element in the array in turn, until it gets back to the beginning. As it goes, it doesn't push back in the elements to be deleted. How does it fare efficiency-wise? This routine touches each data element once, and likely does at most a single implicit array-copy. I think it is probably an O(n+m) operation (n=@hugearray, m=@toremove). The splice solution is O(m log m + m*O(splice(n)). Since perl arrays are not linked lists, I think splice is an O(n) operation, meaning that the splice solutions are O(m log m + m*n). Which is faster? My guess would be the shift-register, but I don't know. In reply to RE: Removing certain elements from an array by BlaisePascal in thread Removing certain elements from an array by Anonymous Monk Title: Use: <p> text here (a paragraph) </p> and: <code> code here </code> to format your post, it's "PerlMonks-approved HTML": Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data! Titles consisting of a single word are discouraged, and in most cases are disallowed outright. Read Where should I post X? if you're not absolutely sure you're posting in the right place. Please read these before you post! — How do I compose an effective node title? How do I post a question effectively? Markup in the Monastery Posts may use any of the Perl Monks Approved HTML tags: a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.) For: Use: & & < < > > [ [ ] ] Link using PerlMonks shortcuts! What shortcuts can I use for linking? See Writeup Formatting Tips and other pages linked from there for more info.

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