distinct values xslt using overriding param or Array - xslt

Question

My xml looks like this:
<topics>
<topic name="topic1" />
<topic name="topic2" />
<topic name="topic3" />
<topic name="topic4" />
<topic name="topic5" />
<topic name="topic6" />
<topic name="topic7" />
</topics>
<supertopics>
<supertopic title="supertopic1" name="1;topic1;#2;#topic2;3;#topic3" />
<supertopic title="supertopic2" name="4;#topic4;#7;#topic7" />
<supertopic title="supertopic3" name="2;#topic2;#3;#topic3" />
<supertopic title="supertopic4" name="5;#topic5;#7;#topic7" />
<supertopic title="supertopic5" name="3;#topic3;#7;#topic7" />
<supertopic title="supertopic6" name="4;#topic4;#7;#topic7" />
<supertopic title="supertopic7" name="5;#topic5;#7;#topic7" />
<supertopic title="supertopic8" name="2;#topic2;#6;#topic6" />
<supertopic title="supertopic9" name="5;#topic6;#7;#topic7" />
<supertopic title="supertopic10" name="3;#topic3;#4;#topic4" />
</supertopics>
I basically want 1 supertopic per topic.So that means I have 7 topics and I want 7 most recent supertopics associated with it. I have date also with it through I m doing sorting but main thing is I want these 7 supertopics to be unique as there are multiple supertopics per topic.
So I want my output to be like this:
supertopic1 (topic1 is associated to supertopic1)
supertopic3 (topic2 is associated to supertopic1 but as its already there i want it to look for next supertopic its associated to)
supertopic5 (topic3)
supertopic2 (topic4)
supertopic4 (topic5)
supertopic8 (topic6)
supertopic6 (topic7)
I am using xsl 1.0
and I was trying to achieve it using but i couldn't find any way to do this:
<xsl:param name="FilteredAssets1">
<stopic></stopic>
<ttopic></ttopic>
</xsl:param>
<xsl:for-each select="topics/topic/#name">
<xsl:variable name="topicname">
<xsl:value-of select="."></xsl:value-of>
</xsl:variable>
<xsl:for-each select="/supertopics/supertopic[contains(#name,$topicname)]">
<xsl:if test="not(contains(msxsl:node-set($FilteredAssets1)/stopic,#title)) and not(contains(msxsl:node-set($FilteredAssets1)/ttopic,$programname))">
<stopic><xsl:value-of select="#title"></xsl:value-of></stopic>
<ttopic><xsl:value-of select="$programname"></xsl:value-of></ttopic>
</xsl:if>
</xsl:for-each>
</xsl:for-each>

Answer 1

This transformation:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:variable name="vSupers"
select="/*/supertopics/supertopic"/>
<xsl:template match="/*">
<xsl:apply-templates select="topics/topic[1]"/>
</xsl:template>
<xsl:template match="topic">
<xsl:param name="pUsedSupers" select="/.."/>
<xsl:variable name="vNewSuper" select=
"$vSupers
[not(#title = $pUsedSupers/#title)
and
contains(concat(#name, ';'),
concat('#', current()/#name, ';')
)
]
[1]
"/>
<xsl:value-of select="concat('
', $vNewSuper/#title)"/>
<xsl:apply-templates select="following-sibling::topic[1]">
<xsl:with-param name="pUsedSupers"
select="$pUsedSupers | $vNewSuper"/>
</xsl:apply-templates>
</xsl:template>
</xsl:stylesheet>
when applied on the provided XML text (wrapped in with a single top element to be made a well-formed XML document and also with acorrection to what I think is a typo for supertopic1):
<t>
<topics>
<topic name="topic1" />
<topic name="topic2" />
<topic name="topic3" />
<topic name="topic4" />
<topic name="topic5" />
<topic name="topic6" />
<topic name="topic7" />
</topics>
<supertopics>
<supertopic title="supertopic1" name="1;#topic1;#2;#topic2;3;#topic3" />
<supertopic title="supertopic2" name="4;#topic4;#7;#topic7" />
<supertopic title="supertopic3" name="2;#topic2;#3;#topic3" />
<supertopic title="supertopic4" name="5;#topic5;#7;#topic7" />
<supertopic title="supertopic5" name="3;#topic3;#7;#topic7" />
<supertopic title="supertopic6" name="4;#topic4;#7;#topic7" />
<supertopic title="supertopic7" name="5;#topic5;#7;#topic7" />
<supertopic title="supertopic8" name="2;#topic2;#6;#topic6" />
<supertopic title="supertopic9" name="5;#topic6;#7;#topic7" />
<supertopic title="supertopic10" name="3;#topic3;#4;#topic4" />
</supertopics>
</t>
produces the wanted, correct result:
supertopic1
supertopic3
supertopic5
supertopic2
supertopic4
supertopic8
supertopic6