Re: Comparing numbers

Hi,
sounds to me like homework.
But ok.
I would write it so :

#!/usr/local/perl -w
use strict;
use warnings;
my @file = ('0.13','0.14','0.14');
my $diff = 0;
my @diffVal;

for (my $i=1 ; $i< scalar(@file) ; $i++){
  if ($diff < abs($file[$i-1]-$file[$i])){
    $diff = abs($file[$i-1]-$file[$i]);
    $diffVal[0] = $file[$i-1];
    $diffVal[1] = $file[$i];
  }
}

print "Difference between $diffVal[0] and $diffVal[1] is $diff\n" if (
+defined($diffVal[1]));
[download]

(It is not optimized!)

Comment on Re: Comparing numbers Download Code

Replies are listed 'Best First'.
Re: Comparing numbers by Abigail-II (Bishop) on Nov 29, 2002 at 11:21 UTC
What's the point of using `-w` and `use warnings`? And why quote numbers? Also, your code seems to fail if all numbers are equal - it won't generate output. Abigail	[reply] [d/l] [select]
Re: Re: Comparing numbers by Chief of Chaos (Friar) on Nov 29, 2002 at 11:28 UTC
ok, `-w` and `use warnings` don't make sense. Yes, you are correct with the equal - output and the numbers. change `my @file = ('0.13','0.14','0.14'); my $diff = 0;` [download] to `my @file = (0.14,0.14); my $diff = -1;` [download] and here you got your output `Difference between 0.14 and 0.14 is 0` [download]	[reply] [d/l] [select]
Re: Re: Comparing numbers by jreades (Friar) on Nov 29, 2002 at 11:28 UTC
You could also have some fun doing something like this: `my @numbers = ('0.13', '0.14', '0.14', '0.19', '0.21', '0.23', '0.45') +; my %differences = (); for (my $i = 0; $i < scalar(@numbers); $i++) { next if $i == 0; push @{$differences{($numbers[$i] - $numbers[$i - 1])}}, $numb +ers[$i] . " - " . $numbers[$i - 1]; } foreach (sort keys %differences) { print STDOUT "Difference ($_) occured: ", join (', ', @{$diffe +rences{$_}}), "\n" } exit 0;` [download] I guess that's going beyond the exercise a little bit, but kind of fun and turned out this: `Difference (0) occured: 0.14 - 0.14 Difference (0.01) occured: 0.14 - 0.13 Difference (0.02) occured: 0.21 - 0.19, 0.23 - 0.21 Difference (0.05) occured: 0.19 - 0.14 Difference (0.22) occured: 0.45 - 0.23` [download]	[reply] [d/l] [select]