面试题50 树中两个结点的最低公共祖先

bool GetNodePath(TreeNode *pRoot, TreeNode *pNode, list<TreeNode *>&path)
{
    if (pRoot == pNode)
        return true;
    path.push_back(pRoot);
    bool found = false;
    vector<TreeNode *>::iterator i = pRoot->m_vChildren.begin();
    while (!found && i < pRoot->m_vChildren.end())
    {
        found = GetNodePath(*i, pNode, path);
        ++i;
    }
    if (!found)
        path.pop_back();
    return found;
}

TreeNode *GetLastCommonNode(const list<TreeNode*>& path1, const list<TreeNode*>& path2)
{
    list<TreeNode*>::const_iterator iterator1 = path1.begin();
    list<TreeNode*>::const_iterator iterator2 = path2.begin();

    TreeNode* pLast = NULL;

    while (iterator1 != path1.end() && iterator2 != path2.end())
    {
        if (*iterator1 == *iterator2)
            pLast = *iterator1;
        iterator1++;
        iterator2++;
    }
    return pLast;
}

TreeNode* GetLastCommonParent(TreeNode* pRoot, TreeNode* pNode1, TreeNode* pNode2)
{
    if (pRoot == NULL || pNode1 == NULL || pNode2 == NULL)
        return NULL;
    list<TreeNode*> path1;
    GetNodePath(pRoot, pNode1, path1);

    list<TreddNode*> path2;
    GetNodePath(pRoot, pNode1, pNode2);

    return GetLastCommonNode(path1, path2);
}