1026. 节点与其祖先之间的最大差值

节点与其祖先之间的最大差值

• 难度: medium
• 原始链接: https://leetcode.cn/problems/maximum-difference-between-node-and-ancestor
• 标签: 深度优先遍历

解法一: 深度优先遍历

go

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func maxAncestorDiff(root *TreeNode) int {
  var dfs func(node *TreeNode, minVal, maxVal int) int
  dfs = func(node *TreeNode, minVal, maxVal int) int {
    if node == nil {
      return maxVal - minVal
    }
    minVal = min(minVal, node.Val)
    maxVal = max(maxVal, node.Val)
    return max(dfs(node.Left, minVal, maxVal), dfs(node.Right, minVal, maxVal))
  }
  return dfs(root, root.Val, root.Val)
}