#!/usr/bin/perl -w
use strict;

my $wunschgewicht = $ARGV[0];
die "Bitte Wunschgewicht angeben!\n" unless $wunschgewicht;

my (@ary, %decl_hash, $erklaer, $best, $cent);
my $diff = 200;

$cent->{" "}      = 0.00; $cent->{"1Cent"}  = 2.30; $cent->{"2Cent"}  = 3.06;
$cent->{"5Cent"}  = 3.92; $cent->{"10Cent"} = 4.10; $cent->{"20Cent"} = 5.74; 
$cent->{"50Cent"} = 7.80; $cent->{"1Euro"}  = 7.50; $cent->{"2Euro"}  = 8.50;

# fill combinational array: 3 coins are combined to a sum and stored 
# in @ary. The explanations are put into %decl_hash.
foreach my $r (keys %$cent){
	foreach my $s (keys %$cent){
		foreach my $t (keys %$cent){
				my $w1 = $cent->{$r};
				my $w2 = $cent->{$s};
				my $w3 = $cent->{$t};
				my $w = $w1 + $w2 + $w3;
				push @ary, $w;
				$decl_hash{$w} ="$r + $s + $t";
		}
	}
}

# test combinations: The composed weights are combined with eachother 
# and the best combination is held in $best respectively $erklaer.
foreach my $i (@ary){
	foreach my $j (@ary){
		my $combin = $i - $j;
		my $d = abs($combin - $wunschgewicht);
		if($d < $diff){
			$best = $combin;
			$diff = $d;
			$erklaer = "( $decl_hash{$i} ) - ( $decl_hash{$j} )";
		}elsif(($d == $diff) && 
			length("( $decl_hash{$i} ) - ( $decl_hash{$j} )") <
			length($erklaer)){
			$best = $combin;
			$diff = $d;
			$erklaer = "( $decl_hash{$i} ) - ( $decl_hash{$j} )";
		}
	}
}


$erklaer =~ s#\ *\+\ +\+\ *# + #g;
$best = sprintf("%.5f", $best);
print "$erklaer = $best Gramm\n";