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The company is investigating the internal data account leakage these days. The reason is that it is found that some interns xiaocute secretly transmitted the source code to GitHub with their account and password, resulting in the leakage of core data. The children still haven't been severely beaten by the society. The consequences of this can b ...

Differences between HashMap and ConcurrentHashMap ConcurrentHashMap divides the whole bucket array into segments, and then protects each segment with a lock lock. Compared with the synchronized lock of HashTable, the granularity of the lock is finer and the concurrency performance is better. However, HashMap has no lock mechanism and is not t ...

1. Foreword Binary Search, also known as Binary Search, is an efficient search method, which can complete the search within the logarithmic time complexity of data scale. Binary Search can be applied to arrays because arrays have the characteristics of random access and arrays are orderly. The mathematical idea of Binary Search is "re ...

This series of articles is the study notes of data structure of Chen Yue and he Qinming of Zhejiang University. The links of the previous series of articles are as follows: Fundamentals of data structure: P1 - Basic Concepts Basic data structure: P2 1 - linear structure - > linear table Basic data structure: P2 2-linear structure - > stac ...

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preface Digital thousandth division, 3-3-4 format splicing of mobile phone number, implementation of trim function, HTML escape, obtaining url query parameters... Do you often encounter them in interviews and work? Let's see how to catch them all with regular!!! 1. Division of thousands of digital prices Change 123456789 to 123456789 I ...

Spring IOC container - Bean management - based on XML 🎈🎈🎈 Spring framework overview Spring is a lightweight open source Java EE frameworkSpring can solve the complexity of enterprise application developmentSpring has two core parts: IOC and AOP IOC: inversion of control, leaving the process of creating objects to Spring for manageme ...

101. Symmetric binary tree Given a binary tree, check whether it is mirror symmetric. For example, a binary tree [1,2,2,3,4,4,3] is symmetric. 1 / \ 2 2 / \ / \ 3 4 4 3 Method 1: recursion Problem solving idea: recurse the left and right subtrees and judge whether they are equal. public boolean isSymmetric(TreeNode root) ...

Usage scenario: when the amount of data fetched reaches a certain level, paging is required for data segmentation. When we do not use the paging function, we will face many problems: Problems with the client: if too much data is displayed on the same page, the user experience will be seriously affected because the page is too long, it is ...

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