• Number of leetcode Islands (200) – BFS zone details


    Give you a two-dimensional grid composed of ‘1’ (land) and ‘0’ (water). Please calculate the number of islands in the grid.Islands are always surrounded by water, and each island can only be formed by adjacent land connections in the horizontal and / or vertical direction.In addition, you can assume that all four sides of the […]

  • Combined search exercise – number of leetcode200 Islands


    Number of islands 1. Title Description LeetCode200:  https://leetcode-cn.com/probl… Give you a two-dimensional grid composed of ‘1’ (land) and ‘0’ (water). Please calculate the number of islands in the grid. Islands are always surrounded by water, and each island can only be formed by adjacent land connections in the horizontal and vertical directions. In addition, you […]

  • [graph theory search topics] how to use “multi-source BFS” to reduce time complexity


    Title Description This is on leetcode“1162. Map analysis”, difficulty is“Medium”。 You now have a grid with the size of , and each cell on it is marked with , and , respectively. Where , represents the ocean and represents the land. Please find an ocean cell. The distance from the ocean cell to the nearest […]

  • [design mode] simple factory


    Factory mode Factory mode: as the name suggests, this class is used to produce products like factories. We are the production class. Factory mode is the mode of creating production classes. It provides a method to create an object in the parent class, allowing the subclass to determine the type of instantiated object. Code binding […]

  • For the city of Guangzhou, Python is used to analyze the real estate market


    The text and pictures of this article come from the network, only for learning and communication, and do not have any commercial purpose. If you have any questions, please contact us in time for handling. The following article is from the author J Ge, who studies python preface Why analyze the real estate market? The […]

  • Android guideview realizes the first login guidance


    Introduction: the lightest novice guide library, can quickly create a mask layer for any view, support a single page, multiple guide tips, support setting different graphics for highlighted areas, support guide animation, and facilitate expansion Project address: binioter / guideview GuideView This system can quickly create a mask navigation page for any view control in […]

  • Yii2 framework user-defined authentication model, complete the login and registration operation example


    This paper describes the user authentication model in yii2 framework, and completes the login and registration operations. The details are as follows: Sometimes we need to define our own user classes and operate our own user tables to complete the login and registration functions. The user table structure is as follows. Of course, you can […]

  • Leetcode 200. Python implementation of island number


    Title Requirements: Thinking: Traverse the array. Whenever you encounter a piece of land, add one to the number of land, and change all the 1’s of this land to 0 Core code: res = 0 cur = [] #Traversing arrays for i in range(len(grid)): for j in range(len(grid[0])): #If the current land is land, change […]

  • Maximum area DFS of front end algorithm Island (depth first search)


    Given a non empty two-dimensional array grid containing some 0 and 1. An island is a combination of adjacent ones (representing land). The “adjacency” here requires that two ones must be adjacent horizontally or vertically. You can assume that all four edges of the grid are surrounded by zeros (representing water). Find the largest island […]

  • Detailed explanation of Ajax login instance based on struts 2 + jquery


    An example of text instrument describes the implementation method of struts 2 + jQuery to realize Ajax login. The specific steps are as follows: 1、 Create a new web project named test. Configure the Struts2 environment, and import the JS file of jQuery to the project. 2、 In com.action Package, create a new one loginAction.java […]

  • JS verification and final landing interface function complete example


    This paper describes the JS verification and final login interface functions. For your reference, the details are as follows: <html> <head> < title > registration page <meta charset=”UTF-8″/> <script type=”text/javascript”> //Verify user name function checkUname(){ //Get user name object var uname=document.getElementById(“uname”).value; //Creating criteria for checking regular expression Var reg = / ^ [[u4e00 – / […]

  • How to install MySQL 8.0 and log in MySQL under Mac OS


    According to the official tutorial, download the installation package, click Install, and set the command path if you want to start from the command line: On the command line, open the configuration file .bash_profile: vim ~/.bash_profile On the last line, add: PATH=$PATH:/usr/local/mysql/bin Press ESC key and input WQ to save and exit. At the command […]