Data commit

Task/24-game-Solve/Perl/24-game-solve.pl

@@ -0,0 +1,54 @@
+# Fischer-Krause ordered permutation generator
+# http://faq.perl.org/perlfaq4.html#How_do_I_permute_N_e
+sub permute :prototype(&@) {
+		my $code = shift;
+		my @idx = 0..$#_;
+		while ( $code->(@_[@idx]) ) {
+			my $p = $#idx;
+			--$p while $idx[$p-1] > $idx[$p];
+			my $q = $p or return;
+			push @idx, reverse splice @idx, $p;
+			++$q while $idx[$p-1] > $idx[$q];
+			@idx[$p-1,$q]=@idx[$q,$p-1];
+		}
+	}
+
+@formats = (
+	'((%d %s %d) %s %d) %s %d',
+	'(%d %s (%d %s %d)) %s %d',
+	'(%d %s %d) %s (%d %s %d)',
+	'%d %s ((%d %s %d) %s %d)',
+	'%d %s (%d %s (%d %s %d))',
+	);
+
+# generate all possible combinations of operators
+@op = qw( + - * / );
+@operators = map{ $a=$_; map{ $b=$_; map{ "$a $b $_" }@op }@op }@op;
+
+while(1)
+{
+	print "Enter four integers or 'q' to exit: ";
+	chomp($ent = <>);
+	last if $ent eq 'q';
+
+	
+	if($ent !~ /^[1-9] [1-9] [1-9] [1-9]$/){ print "invalid input\n"; next }
+
+	@n = split / /,$ent;
+	permute { push @numbers,join ' ',@_ }@n;
+
+	for $format (@formats)
+	{
+		for(@numbers)
+		{
+			@n = split;
+			for(@operators)
+			{
+				@o = split;
+				$str = sprintf $format,$n[0],$o[0],$n[1],$o[1],$n[2],$o[2],$n[3];
+				$r = eval($str);
+				print "$str\n" if $r == 24;
+			}
+		}
+	}
+}