剑指offer——面试题27：二叉树的镜像

函数递归

 1 void MirrorIteratively(BinaryTreeNode* pRoot)
 2 {
 3     if(pRoot == nullptr)
 4         return;
 5 
 6     std::stack<BinaryTreeNode*> stackTreeNode;
 7     stackTreeNode.push(pRoot);
 8 
 9     while(stackTreeNode.size() > 0)
10     {
11         BinaryTreeNode *pNode = stackTreeNode.top();
12         stackTreeNode.pop();
13 
14         BinaryTreeNode *pTemp = pNode->m_pLeft;
15         pNode->m_pLeft = pNode->m_pRight;
16         pNode->m_pRight = pTemp;
17 
18         if(pNode->m_pLeft)
19             stackTreeNode.push(pNode->m_pLeft);
20 
21         if(pNode->m_pRight)
22             stackTreeNode.push(pNode->m_pRight);
23     }
24 }

函数循环