题解 | #二叉树的直径#

import java.util.*;

/*

• public class TreeNode {
• int val = 0;
• TreeNode left = null;
• TreeNode right = null;
• public TreeNode(int val) {

• this.val = val;
  

• }
• } */

public class Solution { int res=0; public int diameterOfBinaryTree (TreeNode root) { dfs(root); return res; } public int dfs(TreeNode root){ if(root==null) return 0; int left=dfs(root.left); int right=dfs(root.right); res=Math.max(res,left+right); return Math.max(left,right)+1; } }