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TreeMap is a Map collection that can compare the size of elements. It will sort the size of the incoming key s. You can use the natural order of elements, or you can use a custom comparator in the collection to sort. The tree structure is realized at the bottom of TreeMap, and a structure of red black tree is realized. TreeMap inherits from Ab ...

Basic introduction Huffman coding, also known as optimal coding, is a coding method and also belongs to a program algorithm.Huffman coding is one of the classical applications of Huffman tree in telecommunications.Huffman coding is widely used in data file compression, and its compression rate is usually between 20% ~ 90%.Huffman coding is ...

350 Intersection of Two Arrays II intersection of two arrays 2 subject attempt First attempt: class Solution { public int[] intersect(int[] nums1, int[] nums2) { Arrays.sort(nums1); Arrays.sort(nums2); int[] nums3 = new int[nums1.length + nums2.length]; int size = 0; for( int i = 0; i < num ...

ConcurrentHashMap is a multi-threaded version of HashMap. HashMap will have various problems during concurrent operation, such as dead circulation, data coverage and so on. These problems can be perfectly solved by using ConcurrentHashMap. Here's the problem. How does ConcurrentHashMap ensure thread safety? How is its bottom layer realized? Nex ...

Basic properties of arrays Array is the simplest data structure. Array is used to store a series of data of the same type. Data is stored continuously and memory is allocated at one time. Insert and delete in the middle of the array. All subsequent data must be moved each time to maintain continuity. The time complexity is O(N). Array index ...

preface In the previous data structure blog post, we have learned about the basic binary tree, but today we will explain in detail the traversal of chain binary tree and various operations. The learning of chain binary tree can exercise our recursive thought and divide and conquer thought very well. Definition of chain binary tree How ...

sketch Recursive order (recursive access) Recursion: access order Recursive order: 1, 2, 4, 4, 2, 5, 5, 5, 2, 1, 3, 6, 6, 3, 7, 7, 7, 3, 1 First order: print the first time in the recursive order, and no operation during the second and third access: 1, 2, 4, 5, 3, 6 and 7 Middle order: print the second time in the recursive order, and ...

📚 Reference book: data structure (C language) - edited by Yan Weimin, Tsinghua University Press. 📖 chart Graph is a more complex data structure than linear table and tree. In the graph structure, the relationship between nodes can be arbitrary, and any two data elements in the graph can be related to each other. The most representative grap ...

I hope to communicate with you and learn from each other through my blog. If you have any mistakes, please correct them in the comment area 1, What is a linked list Sequential tables have defects in space utilization, system consumption and insertion elements. Linked list is the most commonly used dynamic storage method, which overcomes t ...

ArrayList set is one of the most commonly used sets in daily development. It is a linear structure. Its bottom layer is implemented by array, which is equivalent to a dynamic array. Let's take a look at how some common methods of ArrayList are implemented. ArrayList inheritance relationship Interfaces and classes implemented by inheri ...