PS：一下子通过，让我有点不值所措，哈哈哈，菜鸡久了，就会对自己产生怀疑和不自信。挺起胸脯，要自信.
/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: TreeNode* invertTree(TreeNode* root) { //利用前遍历模板 if(root==NULL) return root; //左右孩子先进行交换 TreeNode *temp = root->left; root->left = root->right; root->right = temp; //递归对左右子树进行翻转 invertTree(root->left); invertTree(root->right); return root; } };