--- loncom/homework/response.pm	2004/05/07 17:20:19	1.98
+++ loncom/homework/response.pm	2004/05/27 04:25:13	1.99
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # various response type definitons response definition
 #
-# $Id: response.pm,v 1.98 2004/05/07 17:20:19 albertel Exp $
+# $Id: response.pm,v 1.99 2004/05/27 04:25:13 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -84,26 +84,58 @@ sub end_hintresponse {
     return '';
 }
 
-# used by response to set the non-safe space random number generator to something
-# that is stable and unique based on the part number and response number
+my @randomseeds;
+sub pushrandomnumber {
+    my $rand_alg=&Apache::lonnet::get_rand_alg();
+    if (!$rand_alg || $rand_alg eq '32bit' || $rand_alg eq '64bit' ||
+	$rand_alg eq '64bit2') {
+	# do nothing
+    } else {
+	my @seed=&Math::Random::random_get_seed();
+	push (@randomseeds,\@seed);
+    }
+    &Apache::response::setrandomnumber();
+}
+sub poprandomnumber {
+    my $rand_alg=&Apache::lonnet::get_rand_alg();
+    if (!$rand_alg || $rand_alg eq '32bit' || $rand_alg eq '64bit' ||
+	$rand_alg eq '64bit2') {
+	return;
+    }
+    my $seed=pop(@randomseeds);
+    if ($seed) {
+	&Math::Random::random_set_seed(@$seed);
+    } else {
+	&Apache::lonxml::error("Unable to restore random algorithm.");
+    }
+}
 sub setrandomnumber {
     my $rndseed;
     $rndseed=&Apache::structuretags::setup_rndseed();
     if (!defined($rndseed)) { $rndseed=&Apache::lonnet::rndseed(); }
     &Apache::lonxml::debug("randseed $rndseed");
     #  $rndseed=unpack("%32i",$rndseed);
-    my $rndmod=(&Apache::lonnet::numval($Apache::inputtags::part) << 10);
-    if (defined($Apache::inputtags::response['-1'])) {
-	$rndmod+=&Apache::lonnet::numval($Apache::inputtags::response[-1]);
-    }
-    if ($rndseed =~/,/) {
-	{
-	    use integer;
-	    my ($num1,$num2)=split(/,/,$rndseed);
-	    $num1+=$rndmod;
-	    $num2+=$rndmod;
-	    $rndseed="$num1,$num2";
+    my $rand_alg=&Apache::lonnet::get_rand_alg();
+    my $rndmod;
+    if (!$rand_alg || $rand_alg eq '32bit' || $rand_alg eq '64bit' ||
+	$rand_alg eq '64bit2') {
+	$rndmod=(&Apache::lonnet::numval($Apache::inputtags::part) << 10);
+	if (defined($Apache::inputtags::response[-1])) {
+	    $rndmod+=&Apache::lonnet::numval($Apache::inputtags::response[-1]);
+	}
+    } else {
+	$rndmod=(&Apache::lonnet::numval2($Apache::inputtags::part) << 10);
+	if (defined($Apache::inputtags::response[-1])) {
+	    $rndmod+=&Apache::lonnet::numval2($Apache::inputtags::response[-1]);
 	}
+    }
+    if ($rndseed =~/([,:])/) {
+	my $char=$1;
+	use integer;
+	my ($num1,$num2)=split(/\Q$char\E/,$rndseed);
+	$num1+=$rndmod;
+	$num2+=$rndmod;
+	$rndseed=$num1.$char.$num2;
     } else {
 	$rndseed+=$rndmod;
     }