DEV Community: Suchitra

Design Patterns

Suchitra — Wed, 19 Jun 2024 16:12:26 +0000

This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer.

Explainer

Design patterns are reusable solutions to common software design problems. They guide object creation, composition, and interaction, improving code readability and maintainability. Key types include Creational, Structural, and Behavioral patterns, each addressing specific issues.

Additional Context

Add Live Chat in your website using Chatwoot in just 5 mins.

Suchitra — Wed, 30 Mar 2022 06:10:59 +0000

You will need

A website for embedding Chatwoot
Valid email ID for creating an account on Chatwoot

Step By Step Instruction

Step 1: Create an account for free
Go to the official website and create an account.
In order to create an account, click “Create a free account” and then register yourself by filling out your basic details.

Full Name
Email ID
Account Name
Password
Confirm password

Step 2: Go to setting and then Inbox

After clicking “inbox” then clicking on “Add inbox”, you will see this kind of interface

Now, click on “Website” and enter some details about a website where you want to add live chat.
Like :

Website Name
Website Domain
Widget Color
Welcome heading etc..

See this is a Snapshot of the landing page where we are going to add a live chat system. (Landing page credit : Traversy Media)

Step 3: Add agents to create inbox
You can select yourself as an agent and get it all in your inboxes.
After that, you are just fewer steps to your destination!

Copy the code and paste it into your website code!

Result

Note: This website is statically built with plain HTML, CSS, and a bit of JavaScript, if you want to try similarly then you can just add your copied code into the body tag in the .html file!
Here is the link if you want to see:)

Thanks for reading, if any suggestions feel free to comment below!

If you want to support😀

Send automated emails using n8n.io

Suchitra — Mon, 27 Dec 2021 16:45:09 +0000

You will need

1 Terminal (ex- Git Bash)
2 Email ID

Step-By-Step Guide

Step 1: Install n8n using npm or npx

Install n8n locally on our system, use the below command.
npm install n8n -g

Alternative, If we just want to use n8n without downloading to a local machine, can use this command
npx n8n

In this guide, we will walk you through using npx.

Step 2: Copy the URL and paste it in the address bar

After pasting “http://localhost:5678/” in the address bar, we will get the n8n workflow page.

Now, we are in n8n workflow, where we can use various types of tools to automate the task. So, over here, we will be using the “send email” node for sending the emails using this workflow.

Step 3: Select the “send email” node

Go to the “+” and in the search box type “send email” then select it. After selecting the “send email” node, the below window will pop up.

Note: Before putting the mail address in “from email” make sure that you have the correct and that email account on a service with SMTP support.

If we have a simple email account but in this case, we can also register our email account for SMTP service support by using some SMTP service provider's example elastic email.

Step 4: Create SMTP credentials

Go to Elastic-Email website and create SMTP credentials for your email. After creating, make sure to copy your password.

Now, we are ready to put all the required details for executing our “send email” node.

Step 5: Put all the details for sending the mail from the “send email” node

Click on “SMTP credential” and select the pencil icon and put all the details from the Elasic-Email SMTP details.

Note: In “from email” put only that email which you have provided for SMTP service.

1 Fill the “from email” address
2 “To email” address
3 BCC and CSS email (Optional)
4 Subject
5 Text or HTML form message

If all goes fine then the response will be like the below image

Result

Note: Check the spam folder also, if you don’t find it in your inbox.

Thanks for follow along, hope it helps!

SuchitraFollow

I am enthusiastic about code and technology!!

GitLab Project Guide Step By Step!

Suchitra — Sun, 28 Nov 2021 13:14:11 +0000

You will need

Basic understanding of Git and git commands. There are a lot of resources about Git on the internet. This book is a good place to start.
Git installed on your local system. If you don’t have Git on your device yet, you can download it here.

Step By Step Instructions

Making your first project on GitLab

Step 1:

Go to GitLab website and log in. If you don’t have an account yet, sign up with your credentials. Alternatively, you can sign in with Google, LinkedIn, and other third-party sites.

Step 2: Create a Project

Press “Create a project”, then “Create blank project”. Put in your project’s name (we use “Test”) and a slug (“test”). The slug will show up in the URL of your project on GitLab. Optionally, fill in a project description.
Note: By default, the visibility of your project is private. You can change it to “public” if your project is public-facing and the code doesn’t contain any sensitive data. We changed visibility from “Private” to “Public” in this example.

After completing these steps, your repository will open.Here you can see the “Test” repository is empty and has only a couple of default files: a README with basic user documentation and a GitLab yml file for continuous integration. Learn more about the yml file here.

Step 3: Open git bash and configure git

Use the following commands for git configuration in your terminal or in Git Bash.
git config --global user. name <give username>
git config --global user.email <your email>
Note: If you are not a new user and already have this configured you can skip this step.

Step 4: Make a project folder/directory and initialize git

Make a directory/folder using the following command: mkdir <your foldername>
Open your newly created directory/folder with cd <folder name>
Confirm the directory location with pwd or ls
Then initialize your git repository using git init

Step 5: Make an example text file using the touch command

Here you can change your file according to your requirement.
Open your file on notepad using: notepad <file name>
As you type the notepad <file name> command, the notepad will open as shown below. Then you can update your notepad text file according to your requirements.

Step 6: Check the status, add the file to staging and commit the changes.

Check the current status of your git repository: git status
Then, add all changes in the current directory to the staging area: git add .
Commit the change: git commit -m <commit message>

Step 7: Push your local changes to the remote repository in GitLab

Now use the remote command, followed by the push command, to push the file to the remote repository.
Input and run the following subsequent commands in your terminal:
git remote add origin <remote url>
git remote -v

Now push the local repository to remote GitLab server by using git push -u origin master/main

As you write the push command, this window will pop up for authentication. Put in your GitLab credentials and continue.

Result:

All of your local changes will be checked into version control and reflected on your remote GitLab repository.

Congratulations, you upload your very first project on GitLab using version control

Thanks you reading, hope this guide helps!

Know about 10 popular open-source projects in the end of 2022!

Suchitra — Sat, 20 Nov 2021 11:35:11 +0000

Mozilla Firefox

Mozilla Firefox is an open source web browser developed by Mozilla Foundation.First released in 2002 under the name Phoenix. It's available for most operating systems including Windows, macOS, Linux, and most phones and tablets.

Technologies: C++, C, HTML, JavaScript
List of repositories here

Linux

Linux is a free and open source project developed by Linus Torvald in 1991. Basically, it is an operating system kernel that is open and free for everyone.

Technologies: C, Assembly language
List of repositories here

Apache Cassandra

Apache Cassandra is an open source NoSQL distributed database designed to manage massive amount of structure and unstructured data across the world.
It was developed at Facebook for inbox search and open sourced in July 2008.

Technology: Java
List of repositories here
Top Contributor: Jonathan Ellis, CTO & Co-Founder at DataStax

TensorFlow

TensorFlow is a free and open source software library for Machine Learning and Artificial Intelligence. It was created by Google Brain Team in 2015.

Technologies: Python, C++
List of repositories here

Django

Django is a Python based open source web framework that follows the model template views architectural pattern. It’s design to help developers achieve their most important objective, which rapid development.

Technology: Python
List of repositories here

Kubernetes

Kubernetes is an open source container orchestration system for automating computer application deployment, scaling, and management. It was originally designed by Google and is now maintained by the Cloud Native Computing Foundation.
It aims to provide a "platform for automating deployment, scaling, and operations of application containers across clusters of hosts". It supports a range of container tools, including Docker

Technology: Go
List of repositories here

Ansible

Ansilble is an open source community project sponsored by Red Hat. It is a radically simple IT automation engine that automates cloud provisioning, configuration management, application deployment, intra-service orchestration, and many other IT needs.

Technologies : Python, PowerShell, Shell, Ruby
List of repositories here

Geany

Geany is a small and lightweight IDE that runs on Linux, Windows, MacOS, and every platform that is supported by GTK libraries.

Technologies: C, C++
List of repositories here

Renovate

Renovate is the essential “keep absolutely everything up-to-date” code maintenance tool. Acquired by WhiteSource in November 2019, Renovate is designed to save developers time and reduce security risk by automating dependency updates in software projects.

Technologies: JavaScript, TypeScript
List of repositories here

Jenkins

Jenkins is an open source automation server. It helps automate the part of software development related to building, testing and deploying, facilitating continuous integration and continuous delivery.

Technology: Java
List of repository here

These projects are giant and managed by the community member, not managed by particular ownership. Also, open for everyone who wants to contribute to. Interesting right!!

Thanks for reading, hope it's useful to you

SuchitraFollow

I am enthusiastic about code and technology!!

If you like the contents and want to support:)

Merge Sort and Quick Sort!

Suchitra — Mon, 25 Oct 2021 19:51:09 +0000

In this article I am going to explain two sorting algorithms, Merge Sort and Quick Sort with detailed analysis, application and space and time complexity.

Before starting the topic, let's know about basic and other sorting algorithms.

Some Sorting Algorithms are

Bubble Sort

Easy to implement and easy to understand. But not efficient sort, it takes O(N^2) time complexity and O(1) space. Means it is an in place sorting algorithm.(In each iteration, the biggest element goes into its correct position and in single iteration we have to do more number of swaps).

Selection Sort
Less number of swaps as compared to Bubble Sort. But still not efficient.
It is an in place and unable sorting algorithm with O(N^2) time complexity.
Insertion Sort
It also takes O(N^2) time complexity, but the interesting part of this sorting algorithm is that it takes just O(N) when the elements are partially sorted.
In place and stable sorting, algorithm.
Heap Sort
It is an unstable sorting with O(NlogN) time and O(1) space complexity.
Count Sort

It is a stable sorting algorithm with time complexity O(N + K) where n is the number of elements in the array and k is the range of the elements. Counting sort is most efficient if the range of input values is not greater than the number of values to be sorted. Space O(N + K).
arr = [3, 2, 4, 1, 2] here N = 5, k = 4 - 1 = 3
range of input(N) < number of elements(K)
If range is lager, then it will be not efficient to use.

Now it's time to explain about Merge and Quick sort...

Merge Sort

It is based on Divide and Conquer technique with worst-case time complexity O(NlogN), it is one of most respective algorithms.

Merge Sort first divides the array into equal halves and then merging them in a sorted manner.

Algorithm

Step 1: If only one element in the list, return it.
Step 2: Divide the list recursively into two halves until it can no more divided.
Step 3: Merge the smaller lists into new lists in sorted order(start comparing the elements from two halves of the list, and choose smaller element each time between them and store it into another list(extra space))

Pass copy of original array

import java.util.*;

class Solution {
    public int[] merge_sort(int[] input) {
        if (input.length <= 1) {
            return input;
        }
        int pivot = input.length / 2;
        int[] left_list = merge_sort(Arrays.copyOfRange(input, 0, pivot));
        int[] right_list = merge_sort(Arrays.copyOfRange(input, pivot, input.length));
        return merge(left_list, right_list);
    }

    public int[] merge(int[] left_list, int[] right_list) {
        int[] ret = new int[left_list.length + right_list.length];
        int left_cursor = 0, right_cursor = 0, ret_cursor = 0;

        while (left_cursor < left_list.length && right_cursor < right_list.length) {
            if (left_list[left_cursor] < right_list[right_cursor]) {
                ret[ret_cursor++] = left_list[left_cursor++];
            } else {
                ret[ret_cursor++] = right_list[right_cursor++];
            }
        }
        // append what is remain the above lists
        while (left_cursor < left_list.length) {
            ret[ret_cursor++] = left_list[left_cursor++];
        }
        while (right_cursor < right_list.length) {
            ret[ret_cursor++] = right_list[right_cursor++];
        }
        return ret;
    }
}

class MergeSort {
    public static void main(String args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] arr = new int[n];
        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        // call merge sort function
        arr = merge_sort(arr);
        System.out.print(arr);
    }
}

In place


public class MergeSort {
    public static void main(String[] args) {
        int[] arr = {4, 6, 2, 0, 1, 3};
        mergeSortInPlace(arr, 0, arr.length - 1);
        for (int a : arr)
            System.out.print(a + " ");
    }

    static void mergeSortInPlace(int[] arr, int start, int end) {

        if (start < end) {
            int mid = start + (end - start) / 2;

            mergeSortInPlace(arr, start, mid);
            mergeSortInPlace(arr, mid + 1, end);
            merge(arr, mid, start, end);
        }
    }

    static void merge(int[] arr, int mid, int start, int end) {

        int l = start, r = mid + 1, i = 0;

        int[] mix = new int[end - start + 1];
        while (l <= mid && r <= end) {
            if (arr[l] <= arr[r]) {
                mix[i++] = arr[l];
                l++;
            } else {
                mix[i++] = arr[r];
                r++;
            }
        }
        while (l <= mid) {
            mix[i++] = arr[l++];
        }

        while (r <= end) {
            mix[i++] = arr[r++];
        }

        for (int k = 0; k < mix.length; k++) {
            arr[start + k] = mix[k];
        }

    }
}

Dry Run

Pros and Cons

Pros

Large size list merged by this sort.
Also used in linked list.
External sorting
Stable
Time efficient O(NlogN)

Cons

It takes extra space Need space in the stack(Recursive) logN and extra space N. O(N + logN) = O(N)
Not much efficient for small problem

Quick Sort

Quick sort uses the partition algorithm for finding pivot element and divide the array recursively into two halves.

The idea behind this algorithm is that it is a similar kind of merge sort, but it does not take extra space. Here, the pivot element plays a major role.

What is a pivot element?

choose pivot as 1st element
choose pivot as last element
choose pivot as middle element (Best way)
choose pivot as random element (Best way)

Logic:

Suppose arr = [5, 3, 1, 2, 4]
Step 1: Choose pivot element (took pivot as random so, pivot = 3)
Step 2: In one pass we find pivot is in its proper position, means all the elements which are smaller than pivot are placed in left side and all the elements which are greater than pivot placed right side.(some logic are applied to do so)
Now the array is : 2, 1, 3, 5, 4

Take pivot as an end element


public class QuickSort {
    public static void quickSort(int [] nums, int start, int end) {
        if (start <  end) {
            int partitionIndex = partition(nums, start, end);
            quickSort(nums, start, partitionIndex - 1);
            quickSort(nums, partitionIndex + 1, end);
        }
    }

    public static int partition(int [] nums, int start, int end) {
        int pivot = nums[end];
        int partitionIndex = start;
        for (int i=start; i<end; i++) {
            // lesser than pivot
            if (nums[i] <= pivot) {
                swap(nums, i, partitionIndex);
                partitionIndex += 1;
            }
        }
        swap(nums, end, partitionIndex);
        return partitionIndex;
    }

    public static void swap(int [] nums, int i, int j) {
        int temp = nums[i];
        nums[i] = nums[j];
        nums[j] = temp;
    }

    public static void main(String [] args) {
        int [] nums = {5, 3, 2, 12, 100, 11, 1, 5, 6, 7,83, 4, 45, 56, 7, 4, 3,1};
        quickSort(nums, 0, nums.length - 1);
        for (int number : nums) {
            System.out.print(number + " ");
        }
    }
}

Take pivot as a middle element

package com.example.helloworld;

public class QuickSort {
    public static void quickSort(int [] nums, int start, int end) {
       if(start >= end)return;
       int left = start, right = end;
       int mid = start + (end - start) / 2;
       int pivot = nums[mid];
       while(left <= right){

           while(nums[left] < pivot)left++;
           while(nums[right] > pivot)right--;

           if(left <= right) {
               swap(nums, left, right);
               left++;
               right--;
           }
       }
      //now my pivot at its correct position so, apply same for the two halves recursively!
       quickSort(nums, start, right);
       quickSort(nums, left, end);
    }

    public static void swap(int [] nums, int i, int j) {
        int temp = nums[i];
        nums[i] = nums[j];
        nums[j] = temp;
    }

    public static void main(String [] args) {
        int [] nums = {5, 3, 2, 12, 100, 11, 1, 5, 6, 7,83, 4, 45, 56, 7, 4, 3,1};
        quickSort(nums, 0, nums.length - 1);
        for (int number : nums) {
            System.out.print(number + " ");
        }
    }
}

Useful link

Sorting

Hope it helps, please share your thoughts in the comments ☺️

Hacktoberfest 2021 Guide and Resources!

Suchitra — Mon, 04 Oct 2021 13:31:00 +0000

In this article I am going to explain you everything about Hacktoberfest like what is Hacktoberfest?, why it started, who can take part or who are eligible, what should we do in this program, how it can be beneficial for you etc...

Also, I will provide you some guidance or resources which you can follow in our journey.

So, let's begin...

What is Hactoberfest?

Hacktoberfest is an annual month-long event hosted by Digital Ocean @digitalocean_staff. This is held every year in the month of October.
The aim of this program is to encourage developers to contribute to the open-source projects and give back to the community.
Also, it encourages newbies to learn about open source and help to start their journey towards the open-source contributions.

In my personal opinion If you are new to open source and want to explore or dive deep into it, then it is the best time for you to start.
Via this you can collaborate, learn, interact and network with many people around the world

Who don't know about open source ... can follow this(I am assuming if you are completely new)

How Can you take part in Hacktoberfest?

First, go here and register yourself.
After registering, you will be able to see your profile in this section.

How to contribute as participant?

Participant means you registered yourself as a participant in Hacktoberfest event. And can contribute to the open-source project out there as mentioned the label hacktoberfest and hacktoberfest2021.
Here, your task is to make at least 4 valid and accepted PRs to successfully complete this event. Doing so, you will get some exciting swags and learning opportunity.

Guidance for beginner

After registering yourself, find some projects on GitHub and choose wisely according to your skills and interest.
Explore some projects, try with your own local machine, find some bugs, errors or also if you want some features.
Rise the issue with proper explanation about features/bug etc.
Then if maintainer assign you that issue, start working on that and make a pull request.
After submitting your PR maintainer might be requesting for some changes, so do that as well.
If your change is valid, then maintainer will merge your PR into the main project.
Congratulations, you completed your 1st PR 😀

Completely new!! Don't know how to do this, don't worry, follow this link!

How to contribute as maintainer?

In this event if you want to contribute as maintainer that means you have an existing project, and you want to open source them so that, participant can contribute and make some PRs.
And you are the owner of the project who maintains everything like review the PRs, merge the PRs and other maintainers work.

Why participate in Hacktoberfest?

Although receiving a free t-shirt is always cool, but also there are more important reasons to participate in Hacktoberfest. Whether you are a maintainer or a participant, you will surely learn and benefit a lot from Hacktoberfest

Do's and Don't's

Hacktoberfest is about making a positive impact on open source projects. Please keep this in mind when you're making PRs. Repositories that encourage folks to make a quick PR to win Hacktoberfest, such as simply adding their name to a list or creating collections of algorithms and data structures (DSA) etc., do not follow our values and will not be counted. Hacktoberfest is not about winning a t-shirt, it is about giving back to open source in whatever capacity you can. You can report repos that don't follow our values at https://hacktoberfest.digitalocean.com/report.

Hacktoberfest remains opt-in this year and maintainers must add the hacktoberfest topic to their repository if they wish to participate and for contributions to count. PRs that are made to those repos must then also be accepted by a maintainer to count, either through having an approving review, being merged, or having the hacktoberfest-accepted label added. View the full details at https://hacktoberfest.digitalocean.com/resources/participation.

We also want to focus on maintainers this year and show some appreciation for all the amazing open source work that they do. As part of this, we're offering swag packs to active maintainers during Hacktoberfest, similar to how we reward contributors that make valuable contributions through PRs. Maintainers will need to complete 4 or more actions against PRs in a participating repo to be eligible for a swag pack. View the full details at https://hacktoberfest.digitalocean.com/resources/maintainers.

Some resources which might be helpful to you

Thanks for reading, if you want anything to add, find any mistake or want to give any suggestion please comment it down. I will be happy to see your comments:)

Also, don't forget to mention your projects with your experience about Hacktoberfest which you are interested in.

Happy Hacking!🧡

How to manage your software documentation with docz!

Suchitra — Fri, 24 Sep 2021 06:39:45 +0000

So, before starting the topic, I want to ask you one thing is...

How do you think about documentation of your project?

It's probably boring or time-consuming as well as very tedious task, right!!

But also the documentation is very important part of our project, we can't skip it. Because if project doesn't have the documentation then how much great and useful the project is. It would be useless if no one can understand and use the project.

So, what if you have something which can manage your documentation along with your project. And you can give your full focus on your project, rather of panicking about documentation.
Here, Docz comes into the picture.

So, let get started…

Introduction
What makes Docz a brilliant documentation tool?
Prerequisite
Getting Started with Docz
Conclusion

Introduction to Docz

Documenting code is one of the most important and time-heavy processes when developing software.

A lot of time is spent on building and maintaining custom documentation sites.

Docz was created to solve this problem.

Docz enables you to quickly create live-reloading, seo-friendly, production-ready documentation sites with MDX and customize the look, feel and behavior when required by leveraging GatsbyJS and Gatsby theme shadowing.

In simple, word Docz makes it easy to write and publish beautiful interactive documentation for your code. Create MDX files showcasing your code and Docz turns them into a live-reloading, production-ready site.
It enables you to manage your React components by creating documentation of each component and so that it can help you in your project documentation.
Suppose if you are working on a big and complex project where lots of components are present. In this case, it might be complex to you for understanding each component and managing the component parts. But it would be easy if you use Docz because it will manage everything on behalf of you by creating the docs.
Visit here to know more

Docz is an open source project:

The interesting part of Docz is… it is an open source project, anyone can use and contribute to it (without spending a single penny).
The top contributors and maintainer of this project are Pedro Nauck, Renato Benkerdorf and Rakan Nimer. For know more about contributors and want to contibute. Then go through this link.

Another interesting part of Docz is... Docz itself made up of Docz link.

What makes Docz a brilliant documentation tool?

Powered by Gatsby

Docz is built using GatsbyJS. It's optimised for a lightning-fast development experience and build times. It also allows you to leverage GatsbyJS's massive ecosystem of plugins and tools.

Zero config

It has zero configuration and is easy to learn. Avoid unnecessary build steps with confusing setups.

Easy to customize

Customization is effortless. You can customize the provided theme to make your documentation website stand out.

Based on MDX

MDX is Markdown + JSX. It brings the world of components to Markdown and the best standard for writing documentation.

Fully pluggable

Plugins provide a great way to add functionality to your application without changing your code. Docz supports GatsbyJS plugins and some of the indigenously made Docz plugins.

TypeScript support

Docz provides native TypeScript support for TSX components and can generate documentation from your prop types and comments in your code.

Now, you might be thinking about how can you use it?, what are the prerequisites?, and also might be interested to use it?...

Prerequisite

As, I mentioned the above that it works on component basis, so the prerequisite is... it would be great if you are familiar with React. But don't worry if you don't know It's totally fine, you can still follow along with me.
But I will recommend you to go through the React official documentation. If you want to know more.

Getting Started with Docz

Go to your terminal/cmd/git bash Use this command:

npx create-react-app your-project-name

Note : Don't use capital letters in your project name.
Then

cd your-project-name

Add docz as a dependency

npm install docz

Then, add .mdx files anywhere in your project:

---
name: Button
route: /
---

import { Playground, Props } from "docz";
import Button from "./Button";

# Button

<Props of={Button} />

## Basic usage

<Playground>
  <Button type="submit">Click me</Button>
  <Button>No, click me</Button>
</Playground>

And a Button component, Button.jsx:

import React from 'react';
import t from 'prop-types';

const Button = ({ children, type }) => <button type={type}>{children}</button>

Button.propTypes = {
  /**
   * This is a description for this prop.
   * Button type.
   */
  type: t.oneOf(['button', 'submit', 'reset']),
}
Button.defaultProps = {
  type: 'button',
}
export default Button;

Finally, run:

npx docz dev

This will start a local development server and open your documentation site in the browser.

You can also follow an alternate method to start working with Docz by using create-docz-app.

Conclusion

Managing documentation is not an easy task. But a few communities of developers have made it with products like Docz. Docz’s open source nature makes it affordable, easy to use and create documentation within a heap of seconds.

So, are you excited to use Docz in your next project?
Do let me know in the comment section below. I hope you enjoyed reading.

Do check my article which is officially published here👉 Aviyel

If you want to support😀

Desktop Environment in Linux!

Suchitra — Wed, 25 Aug 2021 17:05:27 +0000

Do you want to use Linux but find difficulty with commands?

So, you came in the right place... In this article, I am going to explain about How can you use Linux in easy way without using any single command!

Here, I will suggest you that it would be great if you go through below 👇 article 1st before starting this.

What is Linux?

Suchitra ・ Apr 10 '21

#linux #beginners

Now, you got to know about Linux and its features as well, also you may or may not be heard about that… Linux is a CLI based, normal user can't use Linux based operating system right!. And If you want to use Linux then you should have good grasp on commands and programming languages.
But don't worry, still you can use Linux!

The solution of your Problem is Desktop Environment.
But here the question arises is ...

What is a Desktop Environment ?

A desktop environment is the bundle of components that provide you common graphical user interface (GUI) elements such as icons, toolbars, wallpapers, and desktop widgets. Thanks to the desktop environment, you can use Linux graphically using your mouse and keyboard like you do in other operating systems like Windows and macOS.
Without a desktop environment, your Linux system will just have a terminal like utility, and you’ll have to interact it using commands only.

Some example of Desktop Environment in Linux:

GNOME

Xfce

LXDE

Budgie

Thanks for reading❤️

If you have any query or suggestions, let me know via commenting!😊

Complete Roadmap to Learn Data Structure and Algorithms 🐱‍🏍👨‍💻👩‍💻

Suchitra — Sun, 04 Jul 2021 12:52:19 +0000

The very 1st step you have to do is, choose a programming language, either Java or C++ (or it's up to you which language you want to learn).

🎯 Now, start learning the language 1st

Like…
📌 Basic Syntax
📌 Data Types
📌 Operators, Variables, functions
📌 Conditional Statement, loops
📌 And the most important OOP(Object-Oriented Programming)

Learn about Collection frameworks if you choose java or STL(Standard Template Library) in C++.
(Or you can skip this as of now).

Now, I can assume that you are a bit familiar with your preferred language.
Like if I say every language has their own unique features/ operations which make them different from others right?

So, my point is that learn the language in such a manner that you don't suffer later.

Suppose, as an example, I am taking Java language here.
So, in this you should know about java…

Whether it is a OOP or procedural language?
And if OOP, whether it is fully OOP or not?
Why java does not support pointers?
Why java is a platform independent language?
Some features of it!

I will encourage you when you start leaning in any language to ask these type of question and try to explore more.

🎯 Now, you learned the language, got familiar with syntax and OPP concepts. So, It's time to deep dive into DSA(Data Structure and Algorithm).

You may or may not be familiar with this term DSA so, I am just briefing you here or in the alternative, you can search into google baba:😀

Let me explain

Data Structure and Algorithms play a vital role in solving problems (industrial problem, real scenario problem, etc…)

Basically, DSA is a very crucial thing in a software field as even in real world scenario as well. In day to day life, you may or may not be notice these, or even we don't have any idea related to it…
Like...

Example 1:

In your phone contacts, you must be search some contacts by their name, right?
Here, have you thought that how fast your phone shows you the results?? Probably in secs or even less, right!

How it searches so fast even we have more than 200 or 500 contacts, but it gets back with results within secs
How??

You would be thinking about that, which algorithm it uses or which data structure it uses…??

So, before knowing the data structure, you should know about Time and Space complexity because of it you can analyze your algorithm that how fast and how efficient it is (It's very important concept)!

What exactly is it, and why is it so important?
So, here Asymptotic Notation comes into picture...in this you will be learning about How can you make your algorithms more efficient or more optimized by reducing their time and space complexity.

Basically this concept is very, very important, or I can say it is a building block of your DSA.
In this, you would learn about…

Two type of Complexities:

Time
Space

Notations:

Big-O Notation (Ο) – Big O notation specifically describes worst case scenario.
Omega Notation (Ω) – Omega(Ω) notation specifically describes best case scenario.
Theta Notation (θ) – This notation represents the average complexity of an algorithm.

Then learn about

O(1)
O(log N)
O(N log N)
O(N)
O(N^2)
O(2^N)
O(N!)

You can follow this book for learning these concept

Example : 2

In your phone suppose you opened multiple websites suppose 1, 2, 3, 4 then you tapped in back what you see means in which order the websites appear…
In this way, right!
4 3 2 1 (LIFO) it is the concept of Stack(Which you will be studying in DS)

Example : 3

In day to day life most of you use Google Map right!
Have you ever thought that how easily google find your specified location and get back to you with some results within secs?
(Basically the Graph concept involves here)

Also involves lots of algorithms and logics behind on it.

Now you would have some idea that how important the DSA is!!

So, without any worry, let's get started. Learn the basic Data Structure.
Like 1st know
Types of DS
It is of two Linear and Non-linear

Linear DS

Array
String
Linked list
Stack
Queue
Hash Table etc…

Non-linear

Tree
Graph
Heap etc…

You can learn these from here
Pick those DS one by one and start to learn those.
Now, you can explore or learn Collection frameworks or STL.

🎯 In mean time pick any one of these HackerRank, HackerEarth, Leetcode, Codechef platform for solving the problems and test your understanding on those topics. I will suggest you that just complete one topic in DSA and try to solve some questions(solve topic wise). In this way, you will get more productive results to grasp the concept!

Now learn some basics Algorithms…

Sorting Algorithms

Bubble Sort
Selection Sort
Insertion Sort
Merge Sort
Quick Sort
Count Sort etc…

👩‍🏫 Learn it here

Searching Algorithms

Linear Search O(N)
Binary Search O(log N)

👩‍🏫 Learn it from here

Recursion :

(Grasp the concept very clearly)
It is a technique in which the function call itself again and again until the base case occurs.

👩‍🏫 Learn it from here

Backtracking :

It is itself a recursion, but here it has some additional conditions which makes it more efficient.

Backtracking is an algorithmic-technique for solving problems recursively by trying to build a solution incrementally, one piece at a time, removing those solutions that fail to satisfy the constraints of the problem at any point of time (by time, here, is referred to the time elapsed till reaching any level of the search tree).

Some standard problems

Sudoku Solver Problem
Rat In Maze
Combination sum, Combination Sum II, Combination Sum III
N Queen Problem

🐱‍🏍 You can visit here
👩‍🏫 Check it here

Greedy Approach :

Greedy is an algorithmic paradigm that builds up a solution piece by piece, always choosing the next piece that offers the most obvious and immediate benefit. So the problems where choosing locally optimal also leads to global solution are best fit for Greedy.
For example, consider the Fractional Knapsack Problem.
👩‍🏫 Check it here

Dynamic Programming:

DP = Recursion + some memory

It has two approach:

Memoization (Top down 👇)
Tabulation (Bottom Up ☝)

You can follow these resources to learn the concept

Bit Manipulation / Bit Masking :

AND (&)
OR (|)
XOR (^)
NOT (~)
Left Shift (<<)
Right Shift(>>)

📌 Learn from here!

👇 Here as well

📌 Another one 😀

Some Advance Topics :

Segment Tree
Tries
Suffix Tree,
Suffix Array,
Advance Graph Theory

Now, it's time to solve problems as much as you can:)
(Practice Makes Man perfect)

Be consistent practicing, initially you will be facing difficulty to solve and even understand the logic by seeing the solution as well. These things are common, it happens to everyone. Just do and don't give up.
(You will be master if you practice 😊)

Participate in contest if you want to test yourself or also interested in CP(Competitive Programming), give it try.

Otherwise, you are good enough for interview if you practice by yourself without giving contest as well!

Some Tips :

While solving problems if you don't come up with solution with spending at most 1 hour, I will suggest you leave that question as for that time no need to spend more time on that!
Try that question another day or some days later. If still stuck, then you can refer to some editorials or hints.
One thing is very important is that suppose you successfully solved some questions 😀. Congratulations, but still I will suggest going to discussion and see other's solution as well. It will be more insightful, and you can get to know different approaches.
And suppose you are in that situation that you can't solve the problem or even seeing the solution, you are unable to think that logic which are used in the solution. So, don't be panic and don't depress. Just dry run the solution, it really helps(Personally it helps me a lot 😊).
If still you are thinking that the concept is not so much clear then try to write on paper what you understand the concept via dry running! (Also, you can refer to video lectures).

Some Free Resources

I hope it helps you 😊

Thanks for reading 🧡

SuchitraFollow

I am enthusiastic about code and technology!!

How to use MongoDB Atlas?

Suchitra — Mon, 28 Jun 2021 16:42:51 +0000

In this article, I am assuming that you have a bit knowledge of MongoDB locally.

Here I will be guiding you How can you use MongoDB Atlas in your website?

So, the prerequisite is some knowledge of MongoDB database, but don't worry if you don't have you can follow this MongoDB docs 👇

https://docs.mongodb.com/manual/tutorial/install-mongodb-on-windows/

In this article, my main focus will be in MongoDB Atlas. So, let get started …

The very 1st step you have to do is go to MongoDB Atlas https://www.mongodb.com/cloud/atlas and sign-up.

After that, login with your credentials.
You will be seeing this page:

You can skip 👇 this process as well, it's totally up to you!

Then you will be seeing this 👇 choose to create cluster Free.

Leave everything as default and click on create cluster!

Enter your credential(username and password) for database connection and remember it or save it somewhere because it will require when you will connect through your website as db connection!

Here, you have to put IP address list so that it can be accessible with only which you will be selected. I have putted 0.0.0.0 (everyone accesses) you can put your personal IP as well.

Boom🎇, you created your very 1st cluster 😀

Now click on connect button!

Click on connect with mongo shell.

If you haven't downloaded the mongo shell before, go through the specified link and download it 1st, its easy and straight forward process.

Now, copy the connection URL.

And open your CMD/ hyper/ git bash anything which you generally use and paste the URL(not required to any specified directory, it will work fine in any directory).

It will ask for password so after entering the password which you initially set, that time I told you that keep safe that password right?
It required here for the mongo DB atlas connection!

If all steps you follow correctly, then you will see this kind of thing in your CMD:
So, Congratulation, you made your connection with MongoDB atlas.

So, the next step is … go to collection in cluster and create your own database and test whether it is working or not!

Here, I am showing you with sample datasets, but you can also create your database, after getting some idea with sample dataset definitely you can create your own database and test it with your mongo shell!

Now, you will be seeing that in your cluster number of sample databases are created, right?

Just go to mongo shell and type:
show dbs
Now you will be seeing all the sample databases which are present in your MongoDB cluster:)

Now, you can also create your database and collection and do test with that as well.

Till now what we did
We created our cluster, connect with mongo shell, created DBs, and tested!

Now, the question arises is that how can we use the database in our website??
So, don't worry!! It's simple(if you have knowledge in MongoDB)

Just go to MongoDB atlas and in cluster go to connect section and
click it.

Now copy the URL

Now you can use this URL in your project, just replace this URL with local MongoDB URL.

See in this blog post website(my project) I have added a Post
What is Linux?

And now it is stored on my MongoDB Atlas

All done, you set your project with MongoDB Atlas.
Test it and congratulations!

Thanks for your patience and do comment if you have any type of suggestions will be appreciated ❤

SuchitraFollow

I am enthusiastic about code and technology!!

Combinations Problem

Suchitra — Wed, 21 Apr 2021 08:27:46 +0000

Before start with the problems of combinations, It will be better if we discuss a bit about it that you should know first!
So, let's discuss…

What is Combination?

In a simple and easy way a combination is a subset of a given set in which order doesn't matter.
Let's understand it better with example
Example - [1, 2, 3]
it's all combinations are - [[], [1], [2], [3], [1, 2], [1, 3], [2, 3] [1, 2, 3]].
Here you might notice that it didn't write in this way - [1, 2] and [2, 1] or [1, 2, 3] and [2, 3, 1] and [3, 1, 2].
Because by the definition we know that order doesn't matter.
Means here [1, 2] = [2, 1]. (anyone we can pick as a combination)
OR [1, 2, 3] = [2, 1, 3] = [3, 1, 2].
If two or more subsets have the same elements and their frequencies are also the same, but the order may or may not be different they considered as a single one(same)!

Representation using tree

                   []
           /                \
        /                      \
      []                       [1]                      
     /  \                     /      \
    []   [2]                [1]     [1, 2]
   / \   /  \              /  \       /   \
  [] [3] [2] [2, 3]      [1] [1, 3] [1, 2] [1, 2, 3]

The above leaf nodes give all combinations of the given array [1, 2, 3]. Here the intuition is pick and don't pick the element in this way we can determine all possible combinations of a given set or array.
Now, I will discuss some basic problem on combinations!

Problem 1

Combinations

Given two integers n and k, return all possible combinations of k numbers out of the range [1, n].

You may return the answer in any order.
Example 1:

Input: n = 4, k = 2
Output:
[
[2,4],
[3,4],
[2,3],
[1,2],
[1,3],
[1,4],
]
Example 2:

Input: n = 1, k = 1
Output: [[1]]
Constraints:

1 < = n < = 20 1 < = k < = n

class Solution {
    public List<List<Integer>> combine(int n, int k) {
        List<List<Integer>> result = new ArrayList<List<Integer>>();
        combination(result, new ArrayList<Integer>(), 1, n, k);
        return result;
    }
    public static void combination(List<List<Integer>> result, List<Integer> list, int start, int n, int k){
        if(k == 0){
        result.add(new ArrayList<>(list));
            return;
        }
        for(int i = start; i <= n - k + 1; i++){ 
            list.add(i);
            combination(result, list, i + 1, n, k - 1);
            list.remove(list.size() - 1);
        }
    }
}

Problem 2

Combination Sum

Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.

The same number may be chosen from candidates an unlimited number of times. Two combinations are unique if the frequency of at least one of the chosen numbers is different.

It is guaranteed that the number of unique combinations that sum up to target is less than 150 combinations for the given input.

Example 1:

Input: candidates = [2,3,6,7], target = 7
Output: [[2,2,3], [7]]
Explanation:
2 and 3 are candidates, and 2 + 2 + 3 = 7. Note that 2 can be used multiple times.
7 is a candidate, and 7 = 7.
These are the only two combinations.
Example 2:

Input: candidates = [2,3,5], target = 8
Output: [[2,2,2,2], [2,3,3], [3,5]]
Example 3:

Input: candidates = [2], target = 1
Output: []
Example 4:

Input: candidates = [1], target = 1
Output: [[1]]
Example 5:

Input: candidates = [1], target = 2
Output: [[1,1]]

class Solution {
    public List<List<Integer>> combinationSum(int[] candidates, int target) {
       // Arrays.sort(candidates);
        List<List<Integer>> res  = new ArrayList();
        find_comboSum(candidates, res, new ArrayList<>(), target, 0);
        return res;
    }
    public static void find_comboSum(int[] arr, List<List<Integer>> res, List<Integer> list, int target, int start){
        if(target < 0)return;
        if(target == 0){
            res.add(new ArrayList(list));
            return;
        }

        for(int i = start; i < arr.length; i++){
            list.add(arr[i]);
        find_comboSum(arr, res, list, target - arr[i], i);
            list.remove(list.size() - 1);

        }
    }
 }

Problem 3

Combination Sum II

Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target.

Each number in candidates may only be used once in the combination.

Note: The solution set must not contain duplicate combinations.

Example 1:

Input: candidates = [10,1,2,7,6,1,5], target = 8
Output:
[
[1,1,6],
[1,2,5],
[1,7],
[2,6]
]
Example 2:

Input: candidates = [2,5,2,1,2], target = 5
Output:
[
[1,2,2],
[5]
]

class Solution {
    public List<List<Integer>> combinationSum2(int[] candidates, int target) {
        Arrays.sort(candidates);
        List<List<Integer>> res = new ArrayList<>();
        find_combo(candidates, res, new ArrayList<>(), target, 0);
        return res;
    }
    public static void find_combo(int[] arr, List<List<Integer>> res, List<Integer> list, int target, int start){
        if(target < 0)return;
        if(target == 0){
            res.add(new ArrayList(list));
            return;

        }
        for(int i = start; i < arr.length; i++){
            if(i > start && arr[i] == arr[i - 1])continue;
            list.add(arr[i]);
            find_combo(arr, res, list, target - arr[i], i + 1);
            list.remove(list.size() - 1);
        }
}
}

Problem 4

Combination Sum III

Find all valid combinations of k numbers that sum up to n such that the following conditions are true:

Only numbers 1 through 9 are used.
Each number is used at most once.
Return a list of all possible valid combinations. The list must not contain the same combination twice, and the combinations may be returned in any order.

Example 1:

Input: k = 3, n = 7
Output: [[1,2,4]]
Explanation:
1 + 2 + 4 = 7
There are no other valid combinations.
Example 2:

Input: k = 3, n = 9
Output: [[1,2,6], [1,3,5], [2,3,4]]
Explanation:
1 + 2 + 6 = 9
1 + 3 + 5 = 9
2 + 3 + 4 = 9
There are no other valid combinations.
Example 3:

Input: k = 4, n = 1
Output: []
Explanation: There are no valid combinations. [1,2,1] is not valid because 1 is used twice.
Example 4:

Input: k = 3, n = 2
Output: []
Explanation: There are no valid combinations.
Example 5:

Input: k = 9, n = 45
Output: [[1,2,3,4,5,6,7,8,9]]
Explanation:
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45
There are no other valid combinations.

Constraints:

2 < = k < = 9
1 < = n < = 60

class Solution {
    public List<List<Integer>> combinationSum3(int k, int n) {
        List<List<Integer>> res = new ArrayList<>();
        if(n < k)return res;
        find_combo(res, new ArrayList<>(), k, 1, n);
        return res;
    }
    public static void find_combo(List<List<Integer>> res, List<Integer> list, int k, int start, int n){

        if(k == list.size() && n == 0){
            res.add(new ArrayList<>(list));
            return;
        }
        for(int i = start; i <= 9; i++){
            list.add(i);
            find_combo(res, list, k, i + 1, n - i);
            list.remove(list.size() - 1);
        }

    }
}

Thanks for reading... if you have any doubts or any suggestions feel free to comment it here and most importantly if you find any bug please let me know. It will be very grateful to me ❤

SuchitraFollow

I am enthusiastic about code and technology!!

DEV Community: Suchitra

Design Patterns

Explainer

Additional Context

Add Live Chat in your website using Chatwoot in just 5 mins.

You will need

Step By Step Instruction

Result

Thanks for reading, if any suggestions feel free to comment below!

Send automated emails using n8n.io

You will need

Step-By-Step Guide

Step 1: Install n8n using npm or npx

Step 2: Copy the URL and paste it in the address bar

Step 3: Select the “send email” node

Step 4: Create SMTP credentials

Step 5: Put all the details for sending the mail from the “send email” node

Result

Thanks for follow along, hope it helps!

SuchitraFollow

GitLab Project Guide Step By Step!

You will need

Step By Step Instructions

Step 1:

Step 2: Create a Project

Step 3: Open git bash and configure git

Step 4: Make a project folder/directory and initialize git

Step 5: Make an example text file using the touch command

Step 6: Check the status, add the file to staging and commit the changes.

Step 7: Push your local changes to the remote repository in GitLab

Result:

Thanks you reading, hope this guide helps!

Know about 10 popular open-source projects in the end of 2022!

Mozilla Firefox

Linux

Apache Cassandra

TensorFlow

Django

Kubernetes

Ansible

Geany

Renovate

Jenkins

Thanks for reading, hope it's useful to you

SuchitraFollow

Merge Sort and Quick Sort!

Some Sorting Algorithms are

Merge Sort

Pass copy of original array

In place

Dry Run

Pros and Cons

Quick Sort

Logic:

Take pivot as an end element

Take pivot as a middle element

Useful link

Hope it helps, please share your thoughts in the comments ☺️

Hacktoberfest 2021 Guide and Resources!

What is Hactoberfest?

How Can you take part in Hacktoberfest?

How to contribute as participant?

Guidance for beginner

How to contribute as maintainer?

Why participate in Hacktoberfest?

Do's and Don't's

Some resources which might be helpful to you

Thanks for reading, if you want anything to add, find any mistake or want to give any suggestion please comment it down. I will be happy to see your comments:)

Happy Hacking!🧡

How to manage your software documentation with docz!

How do you think about documentation of your project?

So, let get started…

Table Of Contents

Introduction to Docz

Docz is an open source project:

What makes Docz a brilliant documentation tool?

Prerequisite

Getting Started with Docz

Conclusion

Desktop Environment in Linux!