Re^2: How would you code this?

I concur that this produces the same output. My main objections to are: a) it uses more decision points to achieve it; b) it messes with the input array (curable).

Thanks for your input.

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Comment on Re^2: How would you code this?

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Re^3: How would you code this? by Marshall (Canon) on Apr 07, 2016 at 20:47 UTC
I made a couple of slight revisions (eliminate the "last" statement and fixed a boundary condition issue at index 0). This still produces the same output. Appreciated your thanks. I leave "what is better" up to you. `#! perl -slw use strict; printf "%s", scalar <DATA>; my @points = map[ split ' ', $_ ], <DATA>; my $i=0; while ($i < @points-2) #quit when there aren't 2 points left { my ($x1,$y1) = @{$points[$i]}; my ($x2,$y2) = @{$points[$i+1]}; if ( ($y2 - $y1 ) / ( $x2 - $x1 ) < 0 ) { splice @points,$i,2; #remove both points $i--; #backup a point to restart $i=0 if $i<0; #boundary condition at index 0 } else { $i++; } } print join ' ', @$_ for @points;` [download]	[reply] [d/l]

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Re^3: How would you code this?
by Marshall (Canon) on Apr 07, 2016 at 20:47 UTC

Appreciated your thanks. I leave "what is better" up to you.

#! perl -slw
use strict;

printf "%s", scalar <DATA>;
my @points = map[ split ' ', $_ ], <DATA>;

my $i=0;
while ($i < @points-2)  #quit when there aren't 2 points left
{   
   my ($x1,$y1) = @{$points[$i]};
   my ($x2,$y2) = @{$points[$i+1]};
   
   if ( ($y2 - $y1 ) / ( $x2 - $x1 ) < 0 )
   {
      splice @points,$i,2; #remove both points
      $i--;                #backup a point to restart
      $i=0 if $i<0;        #boundary condition at index 0
   }
   else
   {
      $i++;
   }
}
print join ' ', @$_ for @points;
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