## leetcode contest 54 solution

• 696. Count Binary Substrings
• 697. Degree of an Array
• 698. Partition to K Equal Sum Subsets
• 699. Falling Squares

## leetcode contest 53 solution

• 691. Stickers to Spell Word
• 693. Binary Number with Alternating Bits
• 694. Number of Distinct Islands
• 695. Max Area of Island

## leetcode contest 52 solution

• 686. Repeated String Match
• 687. Longest Univalue Path
• 688. Knight Probability in Chessboard
• 689. Maximum Sum of 3 Non-Overlapping Subarrays

## 从Huffman编码谈文件压缩

• Huffman编码
• Huffman编码的实现（如何将解压需要用的字典信息写入文件并恢复等）
• LZ77算法
• ZIP（deflate）算法

• LP问题
• 单纯形算法原理
• 无界、无解、循环等情况
• python代码实现

## leetcode 389~399 solution

• 389 Find the Difference
• 390 Elimination Game
• 391 Perfect Rectangle
• 392 Is Subsequence
• 393 UTF-8 Validation
• 394 Decode String
• 395 Longest Substring with At Least K Repeating Characters
• 396 Rotate Function
• 397 Integer Replacement
• 398 Random Pick Index
• 399 Evaluate Division

## leetcode contest 5 solution

• 400 Nth Digit
• 401 Binary Watch
• 402 Remove K Digits
• 403 Frog Jump

## leetcode contest 1 solution

The problems contains:

• 386. Lexicographical Numbers
• 387. First Unique Character in a String
• 388. Longest Absolute File Path

## leetcode Mini Parser

### leetcode Mini Parser

Given a nested list of integers represented as a string, implement a parser to deserialize it.

Each element is either an integer, or a list — whose elements may also be integers or other lists.

Note: You may assume that the string is well-formed:

• String is non-empty.
• String does not contain white spaces.
• String contains only digits `0-9`, `[`, `,`, `]`.

Example 1:

Example 2:

## leetcode Shuffle an Array

### leetcode Shuffle an Array

Shuffle a set of numbers without duplicates.

Example: