剑指offer——面试题23：从上往下打印二叉树

void PrintFromTopToBottom(BinaryTreeNode* pRoot){    if(pRoot == NULL)        return;    std::deque<BinaryTreeNode *> dequeTreeNode;    dequeTreeNode.push_back(pRoot);    while(dequeTreeNode.size())    {        BinaryTreeNode *pNode = dequeTreeNode.front();        dequeTreeNode.pop_front();        printf("%d ", pNode->m_nValue);        if(pNode->m_pLeft)            dequeTreeNode.push_back(pNode->m_pLeft);        if(pNode->m_pRight)            dequeTreeNode.push_back(pNode->m_pRight);    }}