面试题27:二叉树的镜像

二叉树的镜像

题目描述leetcode

题目描述

输入一棵二叉树，输出它的镜像

思路：遍历二叉树，左右儿子交换

void MirrorRecursively(BinaryTreeNode *pNode) { if(pNode==nullptr) return; if(pNode->m_pLeft == nullptr && pNode->m_pRight == nullptr) return; BinaryTreeNode *tmp = pNode->m_pLeft; pNode->m_pLeft = pNode->m_pRight; pNode->m_pRight = tmp; MirrorRecursively(pNode->m_pLeft); MirrorRecursively(pNode->m_pRight); }

leetcode

翻转二叉树 翻转一棵二叉树 class Solution { public: TreeNode* invertTree(TreeNode* root) { if(root == nullptr) return root; if(root->left==nullptr && root->right == nullptr) return root; TreeNode *tmp = root->left; root->left = root->right; root->right = tmp; if(root->left) root->left = invertTree(root->left); if(root->right) root->right = invertTree(root->right); return root; } };

执行用时 : 0 ms, 在Invert Binary Tree的C++提交中击败了100.00% 的用户 内存消耗 : 9.6 MB, 在Invert Binary Tree的C++提交中击败了5.20% 的用户