Leetcode question brushing 1: topic classification

   open LeetCode Website Li Kou Chinese website , If we classify by topic type and quantity , The most common types of questions are arrays 、 Dynamic programming 、 mathematics 、 character string 、 Trees 、 Hashtable 、 Depth-first search 、 Two points search 、 Greedy Algorithm 、 Breadth first search 、 Double pointer and so on .
This book will include the above question types and most of the popular questions on the website , And classify according to the degree of difficulty and type .

   The first big category is Algorithm . This book starts with the simplest greedy algorithm , Then gradually advance to binary search 、 Sorting algorithm and search algorithm , Finally, the dynamic programming and divide and conquer algorithm with high difficulty .– 2/143 –
   The second big category is Mathematics , Including mathematical problems that favor Pure Mathematics , And bit operation problems biased towards computer knowledge . This kind of question is usually used to test whether you are smart , It is not often used in practical work , The author suggests that priority should be given to other categories .
   The third big category is data structures , Include C++ STL Common data structures included in 、 string manipulation 、 Linked list 、 Trees and pictures . among , Linked list 、 Trees 、 And graphs are data structures represented by pointers , And the former is a subset of the latter . Finally, we will also introduce
Introduce some more complex data structures , For example, the classic union search set and LRU.

List of contents involved ：

1. The easiest greedy algorithm to understand
2. Play with the double pointer
3. Two points search
4. Weird sorting algorithm
5. Depth first search and breadth first search
6. Dynamic programming
7. Divide and conquer problem
8. Mathematical problems
9. Magic bit operations
10. Clever use of data structures
11. character string
12. Linked list
13. Trees
14. chart
15. Complex data structures