Programming VIP

Nearest common ancestor of binary tree leetcode link 1. Two solutions Recursion - postorder traversal Idea: this problem wants to find the nearest common ancestor of two nodes, so we have to traverse the tree from bottom to top, judge the two children first, and then judge the logic of the root node, so we think of using post order trav ...

Click to go to PTA topic Input format: The first line of input gives a positive integer n (≤ 50), which is the number of sets. Then, N lines, each line corresponds to a set. Each set first gives a positive integer m (≤ 10 ^ 4), which is the number of elements in the set; then followed by M integers in the [0,10 ^ 9] interval. The nex ...

background Data structure is the basic skill of our programmers, which is often used in daily work and job interview; Moreover, in recent years, the job competition of programmers is becoming greater and greater, and data structures and algorithms have become necessary questions in the interview of large factories. What I know: Huawei technici ...

1, Introduction to particle swarm optimization 1 Introduction The group behavior of birds and fish in nature has always been the research interest of scientists. Biologist Craig Reynolds proposed a very influential bird swarm aggregation model in 19 eight 7. In his simulation, each individual follows: avoid collision with neighboring individua ...

Mainly write: 0-1 backpack, complete backpack (unlimited number of coins in change), multiple backpack (limited number of coins in change), fractional backpack 0-1 backpack: there are N items and a backpack with a capacity of V. each item can only be used once. The volume of article I is v[i], and the value is w[i]. Solve which items are loade ...

1 Basic Concepts Trie tree (dictionary tree), also known as word lookup tree, is a data structure that can efficiently store and find string sets (not limited to strings). In y's eyes, it is a very simple data structure. It includes the following three properties: The root node does not contain characters. Except for the root node, each node ...

The ultimate purpose of studying algorithms is how to spend less time and occupy less memory to complete the same requirements. Cases also demonstrate the differences in time and space consumption between different algorithms, but we can't use time and space. Therefore, Next, we will learn about the description and analysis of algorithm time co ...

Insert sort idea When sorting, each element to be sorted is compared with the previous sorted element. If the reverse order occurs, you need to find a suitable position in the sorted element sequence that can keep it in order, find the insertion position, move the sorted sequence back to make space, and then insert the elements to be sorted; ...

Local ordering of binary search We already know that binary search is a search algorithm for finding a specific element in an ordered array. What if an array is not globally ordered, but locally ordered? At this time, we can use the divide and conquer strategy. We can perform binary search in the locally ordered interval, and then combine eac ...

Multi thread learning 1. Multithreading_ concept Multithreading, in short, is multitasking. Inter method call: an ordinary method call is a closed path from where to where. Multithreading: opens up multiple paths. 2. Multithreading_ Inherit Thread There are three ways to create threads: (1) Inherit Thread(2) Implement Runnable interfac ...