1026. 节点与其祖先之间的最大差值

深碍√TFBOYSˉ_ 2022-12-24 04:54 67阅读 0赞

# 题目来源 #

[1026. 节点与其祖先之间的最大差值][1026.]

# 题目描述 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70_pic_center]

# 题目解析 #

/**
     * 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 {
        
    private int maxDiff = 0;
        public int maxAncestorDiff(TreeNode root) {
        
            if (root == null){
        
                return 0;
            }
            
            helper(root, root.val, root.val);
            return maxDiff;
        }
        
        private void helper(TreeNode root, int max, int min){
        
            if (root.val > max){
        
                max = root.val;
            }
            if (root.val < min){
        
                min = root.val;
            }
            
            maxDiff = Math.max(maxDiff, max - min);
            
            if (root.left != null){
        
                helper(root.left, max, min);
            }
            if (root.right != null){
        
                helper(root.right, max, min);
            }
        }
    }

![在这里插入图片描述][20201126195452267.png_pic_center]

[1026.]: https://leetcode-cn.com/problems/maximum-difference-between-node-and-ancestor/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/4f8c1c01f37f454399b20680e4737a78.png
[20201126195452267.png_pic_center]: https://img-blog.csdnimg.cn/20201126195452267.png#pic_center