226 翻转二叉树 中序遍历

[TanYoh]

翻转二叉树可用中序遍历来做，只是翻转之后依然进入左子树递归

class Solution {
public:
    void invert (TreeNode* cur){
        if (cur!=nullptr){
            invert(cur->left);
            swap(cur->left, cur->right);
            invert(cur->left);
        }
    }
    TreeNode* invertTree(TreeNode* root) {
        invert(root);
        return root;
    }
};