Perl Array Order - arrays

Question

I'am new with perl and stucked with the following exercise.
I have a multi-array and want order its element to descending to the inside arrays sum's.
I want to make the order with Schwartzian transform.
This is my vector:
my #vectors = ( [1], [ 1, 2, 3 ], [4], [ 2, 2, 1 ] );
This is the expected vector:
#sorted_vectors = ( [1,2,3], [2,2,1], [4], [1] );
So far I am tried with these:
(1)
#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
my #vectors = ( [1], [ 1, 2, 3 ], [4], [ 2, 2, 1 ] );
my #sorted_vectors;
# #sorted_vectors = ( [1,2,3], [2,2,1], [4], [1] );
my %hash=();
for(my $i=0;$i< scalar #vectors;$i++){
$hash{$i}=#vectors[$i];
}
for my $key ( sort { $hash{$b}[1] <=> $hash{$a}[1] } keys %hash ) {
push(#sorted_vectors,[#{$hash{$key}}]);
}
print Dumper( \#sorted_vectors );
(2)
#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
my #vectors = ( [1], [ 1, 2, 3 ], [4], [ 2, 2, 1 ] );
my #sorted_vectors;
# #sorted_vectors = ( [1,2,3], [2,2,1], [4], [1] );
my #sorted = map { $_->[0] }
sort { $a->[1] cmp $b->[1] }
map { [$_, foo($_)] }
#vectors;
sub foo{
my $res = 0;
foreach my $x (#_) {
$res+= $x;
}
return $res;
}
print Dumper(\#sorted);

Answer 1

Your code works with few alterations,
my #sorted = map { $_->[0] }
# sort { $a->[1] cmp $b->[1] } # string sort, ascending order
sort { $b->[1] <=> $a->[1] } # numeric sort, descending order
# map { [$_, foo($_)] } # foo() expects list, not array reference
map { [$_, foo(#$_)] } # dereferencing $_ aref for foo()
#vectors;
or same thing but using sum() from core module List::Util
use List::Util 'sum';
my #vectors = ( [1], [ 1, 2, 3 ], [4], [ 2, 2, 1 ] );
my #sorted_vectors = map $_->[0],
sort { $b->[1] <=> $a->[1] }
map [ $_, sum(#$_) ],
#vectors;
use Data::Dumper; print Dumper \#sorted_vectors;
output
$VAR1 = [
[
1,
2,
3
],
[
2,
2,
1
],
[
4
],
[
1
]
];

Answer 2

This is simple with List::UtilsBy::rev_nsort_by and List::Util::sum:
my #vectors = ( [1], [ 1, 2, 3 ], [4], [ 2, 2, 1 ] );
my #sorted = rev_nsort_by { sum #$_ } #vectors;
This sorts the list of #vectors in reverse numerical order (i.e. largest number first) of the result of its control block. The control block here simply sums all the individual elements of each component.