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);
}