今日学习
二叉搜索树的最近公共祖先
题目链接/文章讲解:https://programmercarl.com/0235.%E4%BA%8C%E5%8F%89%E6%90%9C%E7%B4%A2%E6%A0%91%E7%9A%84%E6%9C%80%E8%BF%91%E5%85%AC%E5%85%B1%E7%A5%96%E5%85%88.html
视频讲解:https://www.bilibili.com/video/BV1Zt4y1F7ww
第一想法
利用二叉搜索树的特点,由大小来移动区间
/**
* Definition for a binary tree node.
* function TreeNode(val) {
* this.val = val;
* this.left = this.right = null;
* }
*/
/**
* @param {TreeNode} root
* @param {TreeNode} p
* @param {TreeNode} q
* @return {TreeNode}
*/
var lowestCommonAncestor = function (root, p, q) {
while (root) {
if (root.val > p.val && root.val > q.val) root = root.left
else if (root.val < p.val && root.val < q.val) root = root.right
else return root
}
};
二叉搜索树中的插入操作
题目链接/文章讲解:https://programmercarl.com/0701.%E4%BA%8C%E5%8F%89%E6%90%9C%E7%B4%A2%E6%A0%91%E4%B8%AD%E7%9A%84%E6%8F%92%E5%85%A5%E6%93%8D%E4%BD%9C.html
视频讲解:https://www.bilibili.com/video/BV1Et4y1c78Y
第一想法
保持原先不变的插入操作就没有那么难,只用递归找到合适的空节点,再赋值就好了
/**
* Definition for a binary tree node.
* function TreeNode(val, left, right) {
* this.val = (val===undefined 0 : val)
* this.left = (left===undefined null : left)
* this.right = (right===undefined null : right)
* }
*/
/**
* @param {TreeNode} root
* @param {number} val
* @return {TreeNode}
*/
var insertIntoBST = function (root, val) {
if (root === null) {
let node = new TreeNode(val)
return node
}
if (root.val > val) root.left = insertIntoBST(root.left,val)
if (root.val < val) root.right = insertIntoBST(root.right,val)
return root
};
删除二叉搜索树中的节点
题目链接/文章讲解:https://programmercarl.com/0450.%E5%88%A0%E9%99%A4%E4%BA%8C%E5%8F%89%E6%90%9C%E7%B4%A2%E6%A0%91%E4%B8%AD%E7%9A%84%E8%8A%82%E7%82%B9.html
视频讲解:https://www.bilibili.com/video/BV1tP41177us