Programmer Think

I feel that I haven't learned the part of the tree very well. PTA encountered this problem and didn't write it out at first. After writing it, I found that it's actually very simple. Record it. In fact, what I learned is the process of writing this question That is, if you modify a structure with typedef, you can't define the structure variab ...

Preorder traversal of binary tree Title Description Give you the root node of the binary tree, root, and return the preorder traversal of its node value. Example 1: Input: root = [1,null,2,3] Output:[1,2,3] Example 2: Input: root = [] Output:[] Example 3: Input: root = [1] Output:[1] Method 1: recursion For tree traversal, recursive method ...

Binary tree data structure A tree whose element has at most 2 children is called a binary tree. Because each element in a binary tree can only have two children, we usually name them left and right children. The binary tree node contains the following parts. dataPointer to left childPointer to the right child Binary tree includes: Full bi ...

Heap topK problem - heap sorting The concept of heap ❓ To represent a binary tree with the child's representation (a common representation for brushing questions) is essentially a chain storage. In fact, there is also a sequential storage for the storage of binary trees. To put it bluntly, take an array to store a binary tree, and the way to ...

See you on the topic [CSP-J2020] expression - LuoguKnowledge point analysis: Be able to parse the specified data in the string. This topic requires to parse numbers and logical operators from the string. For ex amp le, x123 only resolves 123 and records it as the 123rd variable. For the convenience of storage, you can save &, |,! Save as a ...

preface Traversal of binary tree is an unavoidable problem to solve the related problems of binary tree. Many problems are solved on the basis of traversal. According to different problems, we can use different traversal methods. According to the order of operations on the root node, it can be divided into: Preorder traversal Middle order tra ...

Title Description input (11,LL) (7,LLL) (8,R) (5,) (4,L) (13,RL) (2,LLR) (1,RRR) (4,RR) () (3,L) (4,R) () output 5 4 8 11 13 4 7 2 1 not complete Idea 1: implement binary tree in pointer mode (chain storage) First define a structure, and then define a structure pointer root as the root node of the whole tree. If the left and right nodes ...

Binary tree The so-called traversal refers to one and only one visit to each node in the tree along a search route. The operation of the access node depends on the specific application problem (for example, print the node content and add 1 to the node content). Traversal is one of the most important operations on a binary tree. It is a bin ...

Recover the binary tree according to traversal In the knowledge of binary tree, finding or traversing binary tree is a very important knowledge point. Because the author only paid attention to the traversal process of binary tree before, but ignored the importance of the inverse process of recovering binary tree from traversal. When I saw an a ...

Brushing date: 7:49 am Sunday, May 30, 2021 Personal question brushing records and code collection are all from leetcode After much discussion and consultation, we now intend to work in the direction of Java The main answer language is Java Title: Sword finger Offer 68 - I. nearest common ancestor of binary search tree Simple d ...