Just for fun, here's your code reworked to be a little more idiomatic:
#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
my @unsortedData = ( 5, 4, 7, 2, 1, 3, 6, 9, 8, 10 );
print "@unsortedData\n";
mergeSort( \@unsortedData );
print "@unsortedData\n";
sub mergeSort {
my( $data ) = @_;
return $data if @$data < 2; # if there is less then two items it'
+s already sorted!!
my $middle = @$data / 2;
my $leftSide = [ @$data[ 0 .. $middle -1 ] ];
my $rightSide = [ @$data[ $middle .. $#{ $data } ] ];
mergeSort( $leftSide );
mergeSort( $rightSide );
merge( $leftSide, $rightSide, $data );
return $data;
}
sub merge {
my ( $groupA, $groupB, $dataRef ) = @_;
my( $i, $j, $k ) = (0)x3;
@$dataRef[$k++] =
$groupA->[$i] <= $groupB->[$j] ? $groupA->[$i++] : $groupB->[$
+j++]
while $i < @$groupA && $j < @$groupB;
@$dataRef[$k++] = $groupA->[$i++] while $i < @$groupA;
@$dataRef[$k++] = $groupB->[$j++] while $j < @$groupB;
}
It also demonstrates something to be aware of; namely, it doesn't use a variable: $sortedData!
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
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In the absence of evidence, opinion is indistinguishable from prejudice.
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