leetcode hot100刷题日记——25.翻转二叉树

class Solution{
public:
    TreeNode* invertTree(TreeNode* root){
        //如果当前节点是空，返回空
        if(root==nullptr){
            return nullptr;
        }
        //翻转左子树
        TreeNode*left=invertTree(root->left);
        //翻转右子树
        TreeNode*right=invertTree(root->right);
        //左右子树交换
        root->left=right;
        root->right=left;
        return root;
    }