# 0.2 重点题纪录

* 3.longest substring without repeating character(hashmap+two pointer)
* 4.Find median of two sorted array
* 5.longest palindromic substring
* 23.Merge K sorted List using merge sort(instead of PQ)
* 31.Next Permutation
* 60.Permutation sequence
* 96.Unique BST I II
* 98.Validate BST
* 109.Convert sorted list to BST
* 124.binary tree maximum path sum
* 146.LRU Cache(Linked List)
* 164.Maximum gap(bucket sort) bug free难，面试写Radix sort
* 215.Kth largest element in array
* 1. Search in a 2D matrix II(取右上角，每次舍弃一列或者一行)
* 267.Permutation II
* 270.Closest Binary Search Tree Value
* 271.Decode and Encode String(length + "#" + string, 不要用s.split("#")), FOLLOW UP: 不记录length
* 295.Find median from data stream(minHeap and maxHeap)
* 324.Wiggle sort II(quickselect & virtual indexing)强记
* 377.Combination Sum IV(top-down and bottom-up)
*


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://syjohnson11.gitbook.io/leetcode/0.-introduction/02_zhong_dian_ti_ji_lu.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.