what's the meaning of the while loop in the 8th problem?

[Yam(长琴)]

    else if(pNode->m_pParent != nullptr)
    {
        BinaryTreeNode* pCurrent = pNode;
        BinaryTreeNode* pParent = pNode->m_pParent;
        while(pParent != nullptr && pCurrent == pParent->m_pRight)
        {
            pCurrent = pParent;
            pParent = pParent->m_pParent;
        }

        pNext = pParent;
    }

what's the meaning of the while loop?

[Yam(长琴)]

oh, i get that