Re: Seeing if two numbers have the same sign

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Re^2: Seeing if two numbers have the same sign
by WoodyWeaver (Monk) on Jan 10, 2008 at 23:36 UTC

sub re {
  my $i=0; /-(?{$i=$i+1})/ for @_; $i=~/0|2/;
}
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x	y	xorNeg()	spaceship()	mult()	anchor()	re()
1	1		1	1	1	1
-1	1				0	1
1	-1				0	1
-1	-1		1	1	1	1

unit square	spaceship	multiply	logic	re
spaceship	--------	worse 21.74%	worse 12.21%	better 86.26%
multiply	better 21.74%	--------	better 10.86%	better 89.25%
logic	better 12.21%	worse 10.86%	--------	better 87.94%
reg exp	worse 86.26%	worse 89.25%	worse 87.94%	--------

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Re^2: Seeing if two numbers have the same sign
by poolpi (Hermit) on Jan 11, 2008 at 09:55 UTC


#!/usr/bin/perl 

use strict;
use warnings;

sub same_sign {
    my $i=0;
    printf( "%2d %2d => ", $_[0], $_[1] );
    s/-/$i=$i+1;/e for @_; 
    $i!~/1/;
}

my $val = [ [ 1, 2 ], [ -1, 2 ], [ 1, -2 ], [ -1, -2 ] ];

for ( 0 .. $#{$val} ) { 
    my ( $x, $y ) = ( $val->[$_][0], $val->[$_][1] );
    print same_sign( $x, $y ) ? '' : 'not ', "same sign\n";
}
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 1  2 => same sign
-1  2 => not same sign
 1 -2 => not same sign
-1 -2 => same sign
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