BuildAllChains()
{
    BuildSubChains(allSets, NULL);
}

BuildSubChains(sets, pParent)
{
    if (sets is empty)
        return;

    trgObj = the most frequent object from sets;

    pNode = new Node;
    pNode->Object = trgObj;
    pNode->pParent = pParent;

    newSets = empty;
    for (each set in sets that contains the trgObj)
    {
        remove trgObj from set;
        remove set from sets;

        if (set is empty)
            set->pHead = pNode;
        else
            newSets.Insert(set);
    }

    BuildSubChains(sets, pParent);
    BuildSubChains(newSets, pNode);
}