Leetcode brush questions: binary tree 05 (flip binary tree)

226. Flip binary tree

Force button topic link

Turn over a binary tree .

package com.programmercarl.tree;

/** * @ClassName InvertTree * @Descriotion TODO * @Author nitaotao * @Date 2022/7/3 12:57 * @Version 1.0 * https://leetcode.cn/problems/invert-binary-tree/ * 226.  Flip binary tree  **/
public class InvertTree {
    
    public TreeNode invertTree(TreeNode root) {
    
        invert(root);
        return root;
    }
    public void invert(TreeNode root) {
    
        if (root == null) {
    
            return;
        }
        TreeNode temp = root.left;
        root.left = root.right;
        root.right = temp;
        invertTree(root.left);
        invertTree(root.right);
    }
}

There is one saying. , I'll take this question , Again AC, I didn't arrive for three minutes from beginning to end . I'm confused after writing .
Do with recursion

1. First judge whether the current node is empty
2. Exchange left and right nodes
3. Enter the left node and perform this step
4. Enter the right node and perform this step

• Finally, let's look at the solution
  

You scared me ... Look again quickly .