DEV Community: vishnu prasath

Hytale server

vishnu prasath — Thu, 15 Jan 2026 06:11:11 +0000

Java25:
To prepare my system for running a hytale server I installed Java 25 using Adoptium.Since Hytale relies on Java for its server-side components having a stable and modern JDK is essential.

link--

adoptium.net/en-GB/temurin/releases

Installing the game files:
And next i have installed the game files in the system where i installed the java25. A command-line tool to download Hytale server and asset files with OAuth2 authentication. See QUICKSTART.md inside the archive.

Download: hytale-downloader.zip (Linux & Windows)

running the server:
java -jar HytaleServer.jar --assets PathToAssets.zip

About my system:
Since my system display is damaged i cant use the main screen to access it so i used a moniter to display and installed secure access to remote servers.

What is SSH?

SSH is a network protocol that allows you to access and control another computer securely through a command-line interface. Unlike older methods like Telnet, SSH encrypts all data, making it safe from attackers and eavesdropping.

Installation:
sudo apt install openssh-server -y
Enable SSH on boot:
sudo systemctl enable ssh
To connect:
ssh username@servername.local

valid Anagram

vishnu prasath — Fri, 31 Jan 2025 12:11:10 +0000

Given two strings s and t, return true if the two strings are anagrams of each other, otherwise return false.
what is anagram?
An anagram is a string that contains the exact same characters as another string, but the order of the characters can be different.

1st method

class Solution:
    def isAnagram(self, s: str, t: str) -> bool:
        if(len(s) != len(t)):
            return False
        charcount = [0]*26
        for i in range(len(s)):
            charcount[ord(s[i]) - ord('a')] += 1  
            charcount[ord(t[i]) - ord('a')] -= 1
        for count in charcount:
            if(count!=0):
                return False
        return True

ord()-Python ord() function returns the Unicode code from a given character. This function accepts a string of unit length as an argument and returns the Unicode equivalence of the passed argument.
eg:ord(‘a’) returns the integer 97, ord(‘€’) (Euro sign) returns 8364

2nd method

class Solution:
    def get_index(self,ch):
         if 'a'<= ch <='z':
            return ord(ch) - ord('a')
         elif 'A'<= ch <='Z':
            return ord(ch) - ord('A')+26
         elif '0'<= ch <='9':
            return ord(ch) - ord('0')+52
    def isAnagram(self, s: str, t: str) -> bool:
        if(len(s) != len(t)):
            return False
        charcount = [0]*62
        for i in range(len(s)):
            charcount[self.get_index(s[i])] += 1  
            charcount[self.get_index(t[i])] -= 1
        for count in charcount:
            if(count!=0):
                return False
        return True

whats different in this method?
In this method the input can be lowercase,uppercase or numbers
why get_index?
using get_index(ch) to map characters to indices:
Lowercase letters ('a'–'z') → indices 0–25
Uppercase letters ('A'–'Z') → indices 26–51
Digits ('0'–'9') → indices 52–61

3rd methond

class Solution:
    def isAnagram(self, s: str, t: str) -> bool:
        return Counter(s)==Counter(t)

what is counter?
Counter is a sub-class that is used to count hashable objects.Counter is an unordered collection where elements are stored as Dict keys and their count as dict value.

Github

vishnu prasath — Wed, 29 Jan 2025 07:01:06 +0000

What is github?
GitHub is a web-based platform that allows developers to store, share, and collaborate on code. It uses Git, an open-source version control system, to track changes to code over time.

How to Generate Personal Access Token in GitHub?
Personal access tokens are an alternative to using passwords for authentication to GitHub when using the GitHub API or the command line.

Step 1: Click on the profile image of your GitHub account
Step 2: Click on Settings
Step 3: Click on <> Developer Settings
Step 4: Click on Personal access tokens
Step 5: Click on Generate new token
Step 6: Add Note and Expiration for your token
Step 7: Select the required scopes
Step 8: Your Personal access token is created successfully

Using this helper will store your passwords unencrypted on disk, protected only by filesystem permissions

git config --global credential.helper store

git push-The git push command is used to transfer or push the commit
git pull-If you make a change in a repository, GIT PULL can allow others to view the changes

Data structures-1

vishnu prasath — Wed, 02 Oct 2024 12:18:23 +0000

Data structures:
->Data structures are ways of organizing and storing data in a computer so that it can be accessed and modified efficiently. They are fundamental to computer science and are used in various applications to manage and process data.

Arrays:
->An array is a collection of elements, with each element in the array having an index value that starts from 0 and goes up to
n−1, where 𝑛 is the total number of elements in the array.

Example:
Imagine a passenger train that has a fixed number of compartments, say 5 compartments. Each compartment can hold a certain number of passengers.

Arrangement of Compartments:
1.The compartments are numbered from 0 to 4 (for a total of 5 compartments).
2.You can think of the compartments as an array, where each index represents a compartment number.

The arrangement looks like this:

Compartment 0: Empty
Compartment 1: Empty
Compartment 2: Empty
Compartment 3: Empty
Compartment 4: Empty

Boarding the Train:
1.Passengers A, B, and C enter Compartment 0.
2.Passengers D and E enter Compartment 1.
3.Passenger F enters Compartment 2.

Now the arrangement of the compartments looks like this:

Compartment 0: Passenger A, Passenger B, Passenger C
Compartment 1: Passenger D, Passenger E
Compartment 2: Passenger F
Compartment 3: Empty
Compartment 4: Empty

Unloading Passengers:
1.When the train reaches its destination, Passengers A, B, and C get off from Compartment 0. After this, the compartments look like this:

Compartment 0: Empty
Compartment 1: Passenger D, Passenger E
Compartment 2: Passenger F
Compartment 3: Empty
Compartment 4: Empty

Stack:
->A stack is a linear data structure that follows the Last In, First Out principle. This means that the last element added to the stack is the first one to be removed.

Example:
simple stack example using bangles in the hand

Pushing a Bangle:
1.You start with an empty hand.
2.You place "Bangle A" on your palm.
3.Next, you add "Bangle B" on top of "Bangle A"
4.Finally, you add "Bangle C" on top of "Bangle B"

Your hand now looks like this

[Bangle C]
[Bangle B]
[Bangle A]

Popping a Bangle:
1.When you want to remove a bangle, you take "Bangle C" off the top of the stack.

Your hand now looks like this:

[Bangle B]
[Bangle A]

Queue:
->A queue is a linear data structure that follows the First In, First Out principle. This means that the first element added to the queue is the first one to be removed, similar to a line of people waiting for service.

Example:
Imagine there’s a bookstore with a line of people waiting outside to buy books.

People Arriving:
1.Person A arrives first and stands at the front of the line.
2.Then, Person B arrives and stands behind Person A.
3.Next, Person C arrives and stands behind Person B.

The line now looks like this:

Front -> Person A
         Person B
         Person C <- Rear

Serving Customers:
1.The shop opens, and the cashier starts serving the first person in line.
2.Person A is the first to be served and buys their books. After this, they leave the line

The line now looks like this:

Front -> Person B
         Person C <- Rear

Java learning-2

vishnu prasath — Wed, 02 Oct 2024 08:14:51 +0000

1.Why java is not purely object oriented programming?
->Java is not a purely object oriented programming language because it uses primitive data types such as int,char,bool,etc.
->java is mostly object oriented programming language and not purely object oriented.

Abstract class:
->Java abstract class is a class that cannot be instantiated by itself, it needs to be subclassed by another class to use its properties. An abstract class is declared using the “abstract” keyword in its class definition.

Example:

abstract class Shape
{
  int color;
  //An abstract function
  abstract void draw();
}

Interface:
->Another way to achieve abstraction in Java, is with interfaces.
To access the interface methods, the interface must be "implemented" by another class with the implements keyword

Example for interface:

interface Animal {
  public void animalSound(); // interface method (does not have a body)
  public void run(); // interface method (does not have a body)
}

Example for implements:

public interface Animal {
    void makeSound();
    void eat();
}
public class Dog implements Animal {
    public void makeSound() {
        System.out.println("Woof!");
    }
    public void eat() {
        System.out.println("Dog is eating.");
    }
}

Abstract class vs Interface:
Abstract class->Use when class are closely related,share common code and need to have default behaviour.
Interface->Use when you want to define a contract that unrelated class can implement and when multiple inheritance is needed.

Java learning part-1

vishnu prasath — Sat, 28 Sep 2024 07:45:49 +0000

Today i learned about the basics of java programming language.
First i saw about class and objects
Class-A blueprint for creating objects. It can contain methods (functions) and fields (variables).
Objects-An instance of a class. It allows access to the class's members (methods and fields).

class A{
 int a;
 public void set(int n){
  a=n;
 }
 public int get(){
  return a;
  }
}
public class Main {
    public static void main(String[] args) {
     A a=new a();
     a.set(5);
     System.out.println("a.get());
     A a2=new A();
     System.out.println(a2.get());
   }
}

Command line arguments:
It is used to pass the arguments by the users while executing the program.

Void:The void keyword specifies that a method should not have a return value.

String[] args - here args can be any name like program,java,main,etc.

Static variable can be accessed by objects if the value assigned in the class.

Access specifier:
There are four types of access specifier they are
1.private
2.public
3.default
4.protected

1.private: Accessible only within the class where it is declared.
2.public: Accessible from any other class.
3.default (no modifier): Accessible only within classes in the same package.
4.protected: Accessible within the same package and by subclasses in other packages.