0783. Minimum Distance Between B S T Nodes

# 783. Minimum Distance Between BST Nodes#

## 题目 #

Given the `root` of a Binary Search Tree (BST), return the minimum difference between the values of any two different nodes in the tree.

Note: This question is the same as 530:  https://leetcode.com/problems/minimum-absolute-difference-in-bst/

Example 1:

``````Input: root = [4,2,6,1,3]
Output: 1
``````

Example 2:

``````Input: root = [1,0,48,null,null,12,49]
Output: 1
``````

Constraints:

• The number of nodes in the tree is in the range `[2, 100]`.
• `0 <= Node.val <= 10^5`

## 解题思路 #

• 本题和第 530 题完全相同。解题思路见第 530 题。

## 代码 #

``````package leetcode

import (
"math"

"github.com/halfrost/leetcode-go/structures"
)

// TreeNode define
type TreeNode = structures.TreeNode

/**
* Definition for a binary tree node.
* type TreeNode struct {
*     Val int
*     Left *TreeNode
*     Right *TreeNode
* }
*/

func minDiffInBST(root *TreeNode) int {
res, nodes := math.MaxInt16, -1
dfsBST(root, &res, &nodes)
return res
}

func dfsBST(root *TreeNode, res, pre *int) {
if root == nil {
return
}
dfsBST(root.Left, res, pre)
if *pre != -1 {
*res = min(*res, abs(root.Val-*pre))
}
*pre = root.Val
dfsBST(root.Right, res, pre)
}

func min(a, b int) int {
if a > b {
return b
}
return a
}

func abs(a int) int {
if a > 0 {
return a
}
return -a
}
``````

Apr 8, 2023