use strict; use warnings;
my @arr = ('foo','bar','qux','foo1','bar1','qux1');
my %hash =
(
	'4-5' => '0.750',
	'0-4' => '0.167',
	'0-2' => '0.600',
	'2-3' => '0.200',
	'2-4' => '0.300',
	'0-3' => '0.300',
	'2-5' => '0.400',
	'1-2' => '0.550',
	'1-5' => '0.273',
	'3-4' => '0.300',
	'1-4' => '0.182',
	'0-1' => '0.917',
	'3-5' => '0.400',
	'0-5' => '0.250',
	'1-3' => '0.300'
);

my @nodew;
for ( keys %hash )
{
	my $v = $hash{$_};
	$nodew[$_] += $v for /(\d+)/g;
}

my @sorted_node_indices = sort {
	$nodew[$a] <=> $nodew[$b]
} 0 .. $#nodew;

my @arr_sorted = @arr[ @sorted_node_indices ];

##</code><code>##

use strict; use warnings;
my @arr = ('foo','bar','qux','foo1','bar1','qux1');
my %hash =
(
	'4-5' => '0.750',
	'0-4' => '0.167',
	'0-2' => '0.600',
	'2-3' => '0.200',
	'2-4' => '0.300',
	'0-3' => '0.300',
	'2-5' => '0.400',
	'1-2' => '0.550',
	'1-5' => '0.273',
	'3-4' => '0.300',
	'1-4' => '0.182',
	'0-1' => '0.917',
	'3-5' => '0.400',
	'0-5' => '0.250',
	'1-3' => '0.300'
);

my %edgew;

for ( keys %hash )
{
	my( $from, $to ) = @arr[ /(\d+)/g ];
	$edgew{$from}{$to} = 
	$edgew{$to}{$from} = $hash{$_};
}

for my $from ( sort keys %edgew )
{
	print "$from:\n";
	print "\t$_ : $edgew{$from}{$_}\n" for 
		sort { $edgew{$from}{$a} <=> $edgew{$from}{$b} }
		keys %{ $edgew{$from} };
}