543.二叉树的直径

这里写自定义目录标题

• 题目描述
• 题目解答

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题目描述

题目解答

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    int res = 0;
    public int depth(TreeNode node) {
        if(node == null){
            return 0;
        }
        int left = depth(node.left);
        int right = depth(node.right);
        res = Math.max(res,left+right);
        return Math.max(left,right)+1;
    }    
    public int diameterOfBinaryTree(TreeNode root) {
        depth(root);
        return res;
    }
}