# reisinge
perl -E 'say [ sort { $ARGV[$b] <=> $ARGV[$a] } 0..$#ARGV ]->[0]' 42 1
+000 999 0 -1
# GrandFather
perl -E '$m=0; $ARGV[$m] > $ARGV[$_] or $m=$_ for 1..$#ARGV; say $m' 4
+2 1000 999 0 -1
# Shorten, similar performance
perl -E '$i=0; ($ARGV[$m] > $_ or $m=$i), $i++ for @ARGV; say $m' 42 1
+000 999 0 -1
Below, please find a benchmark script for testing against a large list.
use strict;
use warnings;
use List::Util 'shuffle';
use Time::HiRes 'time';
# Return index to biggest element.
sub reisinge {
[ sort { $_[$b] <=> $_[$a] } 0 .. $#_ ]->[0];
}
sub GrandFather {
my $idxMax = 0;
$_[$idxMax] > $_[$_] or $idxMax = $_ for 1 .. $#_;
$idxMax;
}
sub biggest_elm {
my ($idxMax,$idx) = (0,0);
($_[$idxMax] > $_ or $idxMax = $idx), $idx++ for @_;
$idxMax;
}
srand 0;
my @list = shuffle 1..4e5;
for my $code (qw( reisinge GrandFather biggest_elm )) {
no strict 'refs';
my ($start, $idx) = (time, $code->(@list));
printf "Index %d, Seconds (%-11s): %0.03f\n",
$idx, $code, time - $start;
}
Regards, Mario.
Edit: Added benchmark script. |