Re: Fast way to check if a sort was doen

Couldn't you make a flag variable and define a sort block? Concept:

$changed = 0;
my @array = sort {
  my $result = ($a cmp $b);
  $changed = 1  if $result==1; # Only set changed if $a > $b
  $result
} @oldarray;
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Comment on Re: Fast way to check if a sort was doen Download Code

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Re^2: Fast way to check if a sort was doen by dewey (Pilgrim) on Jun 28, 2007 at 19:27 UTC
I like this idea, but I couldn't get it to work. `my @oldarray = (0..9); my @array = sort { my $result = ($a cmp $b); print "$result "; $result } @oldarray; print "\n@array\n";` [download] printed these results: `-1 -1 -1 -1 -1 -1 1 -1 1 1 1 -1 1 -1 1 1 1 1 1 0 1 2 3 4 5 6 7 8 9` [download] Without knowing exactly how the sorting algorithm is implemented, I don't see how we could reliably use this kind of method. If OP wants to write a sorting function, they can include a flag... otherwise, this problem seems pretty solidly O(N) to me. ~dewey	[reply] [d/l] [select]

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Re^2: Fast way to check if a sort was doen
by dewey (Pilgrim) on Jun 28, 2007 at 19:27 UTC

my @oldarray = (0..9);

my @array = sort {
    my $result = ($a cmp $b);
    print "$result ";
    $result
    } @oldarray;

print "\n@array\n";
[download]

-1 -1 -1 -1 -1 -1 1 -1 1 1 1 -1 1 -1 1 1 1 1 1 
0 1 2 3 4 5 6 7 8 9
[download]

~dewey

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