Author: waliwali

Problem Guidance: In the process of learning HashMap, you will encounter the question that to ensure the uniqueness of the key, you need to override the hashCode method, and the equals method.Why do we need to cover the hashCode method and the equals method in order to ensure the uniqueness of the key?   The analysis process is as follows: HashMapProcess: 1.Each object generates a shaping value (hash code) through the hashCode () method. 2.Handling hash codes: In the case of HashMap inserting objects and querying objects, the following processes are performed: 1.HashMapIt checks to see if th...

package stack import "errors" type Stack []interface{} func (s *Stack) Len() int { return len(*s) } func (s *Stack) Cap() int { return cap(*s) } func (s *Stack) Push(x interface{}) *Stack { *s = append(*s, x) /** If it is changed toZ: = append (*s, x)S = & Z1. Instead of assigning a function return value to a variable, address a function directly: like this: s = amp; (append (* s, x))It is not allowed.The reason may be that the return value of a function is a local variable that is scoped inside the function, and if no value is passed to an external calle...

[Reprint] 1.Network level division In order to enable computers produced by different computer manufacturers to communicate with each other so as to establish computer networks in a wider range, the International Organization for Standardization (ISO) in 1978 proposed the Open System Interconnection Reference Model (OSI/RM Model).Nterconnection/Reference Model). It divides the communication protocol of computer network architecture into seven layers, which are Physics Layer and Data Link Lay from bottom to top.Er, Network Layer, Transport Layer, Session Layer, Presentation Layer, Applicati...

People always follow a variety of rules in their daily life. These rules come from the law, followed by the law.Moral constraints，Beyond the explicit rules and conventions, there is a more subtle measure of the normality of one’s conduct, that of others.The usual pattern of behavior.“Normal is a vague word, and no one has a particular definition of it. It is measured by other people’s behavior. And who else is it? Most people. However, this can not be quantified.Cry when your loved ones die, be happy when your friends get together, be surprised when you receive a gift, and com...

First. 　　As mentioned earlier, the “SQL Server Backup and recovery series” is focused on the user database. SQL server also maintains a set of system databases that are critical to the running of server instances. After each system update, multiple systems must be backed up.According to the library. The system database that must be backed up includes: MSDB, master, model. If you use replication, you need to back up the distribution library. Backup is used to restore the system when it fails to prevent system failure. 　　1.masterDatabase introduction 　　　　masterThe da...

[notes] Bashi game Define Bashi game is the simplest game, defined as follows There is only a pile of n items, two people take turns from the pile of goods, the provisions of at least one at a time, a maximum of M. Finally, the winner wins. Victory state\(N\)And must defeat state\(P\) All winning States\(N\)There must be a way to move to defeat.\(P\) Abortive state\(P\)No matter how it is transferred, it will be transferred to victory.\(N\)(Win the next battle. All endpoints must be defeated.\(P\) Analysis of victory\(N\)And must defeat state\(P\)Starting from the endpoint, we analyze th...