C++ SearchTreeNode::RecalcDepth方法代码示例

nSearchTreeNode BasicSearchTree::SplitBranch(nSearchTreeNode n,size_t depth)
{
    if (!n || !m_Nodes[n] || m_Nodes[n]->GetDepth()==depth)
        return n;
    // for !n it returns the rootnode
    // for !m_Nodes[n], it fails by returning n.
    // for m_Nodes[n]->GetDepth()==depth, it's a special case (given position is a node)
    // so we just return n.

    SearchTreeNode* child = m_Nodes[n];

    nSearchTreeNode old_parent = child->GetParent();

    // Create new node "middle", add it to old_parent in place of child.

    // Calculate the parent offset and the new labels' parameters.
    size_t parent_offset = depth - child->GetLabelStartDepth();
    nSearchTreeLabel labelno = child->GetLabelNo();

    unsigned int oldlabelstart = child->GetLabelStart();
    unsigned int oldlabellen = child->GetLabelLen();

    unsigned int middle_start = oldlabelstart;
    unsigned int middle_len = parent_offset;

    unsigned int child_start = middle_start + middle_len;
    unsigned int child_len = oldlabellen - middle_len;

    wxChar middle_char = m_Labels[labelno][middle_start];
    wxChar child_char = m_Labels[labelno][child_start];

    // Now we're ready to create the middle node and update accordingly

    SearchTreeNode* newnode = CreateNode(depth,old_parent,labelno,middle_start,middle_len);
    m_Nodes.push_back(newnode);
    nSearchTreeNode middle = m_Nodes.size() - 1;

    // Add child to middle
    child->SetParent(middle);
    child->SetLabel(labelno,child_start,child_len);
    child->RecalcDepth(this);
    newnode->m_Children[child_char]=n;
    child->UpdateItems(this);

    // Add middle to old_parent
    m_Nodes[old_parent]->m_Children[middle_char]=middle;

    return middle;
}

SearchTreePoint BasicSearchTree::AddNode(const wxString& s, nSearchTreeNode nparent)
{
    SearchTreePoint result(0,0);
    nSearchTreeNode n = 0;
    bool found = this->FindNode(s,nparent,&result);
    if (!found)
    {
        // Create new node

        // If necessary, split the edge with a new node 'middle'
        // If result is exactly a node, middle will be just result.n.
        nSearchTreeNode middle = SplitBranch(result.n,result.depth);

        // Now add the node to the middle node
        SearchTreeNode* newnode;
        wxString newlabel;
        if (m_Nodes[middle]->IsLeaf())
        {
            // If it's a leaf node, just extend the label and change
            // the new node's depth to reflect the changes.
            n = middle;
            newnode = m_Nodes[n];

            // We take the part of the string that corresponds to node middle.
            // Since s starts at nparent's depth, we just get the difference and
            // it will be the position inside the string.
            newlabel = s.substr(m_Nodes[middle]->GetLabelStartDepth() - m_Nodes[nparent]->GetDepth());

            // Modify the leaf node's label to extend the point
            // Since it's a leaf node, we just concatenate to the current label the missing part.
            unsigned int oldlen = newnode->GetDepth() - newnode->GetLabelStartDepth();
            if (oldlen < newlabel.length()) // Safety check against segfaults
            {
                m_Labels[newnode->GetLabelNo()] << newlabel.substr(oldlen);
                m_Labels[newnode->GetLabelNo()].Shrink();
            }
            newnode->SetLabel(newnode->GetLabelNo(),newnode->GetLabelStart(),newlabel.length());
            newnode->RecalcDepth(this);
        }
        else
        {
            // Get the string's depth. This will be the depth of our new leaf node.
            size_t newdepth = m_Nodes[nparent]->GetDepth() + s.length();

            // start = middle's depth - nparent's depth.
            newlabel = s.substr(m_Nodes[middle]->GetDepth() - m_Nodes[nparent]->GetDepth());

            // Now we create the new label to be accessed by the leaf node "newnode".
            m_Labels.push_back(newlabel);
            nSearchTreeLabel nlabel = m_Labels.size() - 1;
            m_Labels[nlabel].Shrink();

            // Finally, we create the new node and link it to "middle".
            newnode = CreateNode(newdepth,middle,nlabel,0,newlabel.length());
            m_Nodes.push_back(newnode);
            n = m_Nodes.size()-1;
            m_Nodes[middle]->m_Children[newlabel[0u]]=n;
        }
        result.n = n;
        result.depth = newnode->GetDepth();

    }
    return result;
}