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95 lines
1.8 KiB
Markdown
95 lines
1.8 KiB
Markdown
# [783. Minimum Distance Between BST Nodes](https://leetcode.com/problems/minimum-distance-between-bst-nodes/)
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## 题目
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Given the `root` of a Binary Search Tree (BST), return *the minimum difference between the values of any two different nodes in the tree*.
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**Note:** This question is the same as 530: [https://leetcode.com/problems/minimum-absolute-difference-in-bst/](https://leetcode.com/problems/minimum-absolute-difference-in-bst/)
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**Example 1:**
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```
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Input: root = [4,2,6,1,3]
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Output: 1
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```
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**Example 2:**
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```
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Input: root = [1,0,48,null,null,12,49]
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Output: 1
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```
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**Constraints:**
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- The number of nodes in the tree is in the range `[2, 100]`.
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- `0 <= Node.val <= 10^5`
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## 题目大意
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给你一个二叉搜索树的根节点 root ，返回 树中任意两不同节点值之间的最小差值 。
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## 解题思路
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- 本题和第 530 题完全相同。解题思路见第 530 题。
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## 代码
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```go
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package leetcode
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import (
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"math"
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"github.com/halfrost/LeetCode-Go/structures"
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)
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// TreeNode define
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type TreeNode = structures.TreeNode
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/**
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* Definition for a binary tree node.
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* type TreeNode struct {
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* Val int
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* Left *TreeNode
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* Right *TreeNode
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* }
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*/
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func minDiffInBST(root *TreeNode) int {
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res, nodes := math.MaxInt16, -1
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dfsBST(root, &res, &nodes)
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return res
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}
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func dfsBST(root *TreeNode, res, pre *int) {
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if root == nil {
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return
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}
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dfsBST(root.Left, res, pre)
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if *pre != -1 {
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*res = min(*res, abs(root.Val-*pre))
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}
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*pre = root.Val
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dfsBST(root.Right, res, pre)
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}
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func min(a, b int) int {
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if a > b {
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return b
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}
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return a
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}
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func abs(a int) int {
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if a > 0 {
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return a
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}
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return -a
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}
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``` |