DEV Community: Kaushal

Valid Parantheses

Kaushal — Tue, 14 Apr 2026 02:42:17 +0000

I recently was looking at this question and I don't know about all but I definitely was not aware of real-world use case of this DSA and Algorigthm question. I didn't just learned more about Stack Data Structure but I learned how and where in the real world this is being used.

A number of places:

Browser navigation button it uses a Stack
Normal copy and paste mechanism on computers uses Stack to add changes in one stack and remove from the other one and vice versa
JS Call stack ofcourse how can that be missed
Code editor's syntax highlighting and fixing

The most fascinating thing for me was the Code Editor's syntax validation because the "Valid Parantheses" leetcode problem was a pain in the beginning for me but now I visualize it in my mind easily because I work with code every day I look at the brackets everyday so now it all makes sense how that problem will be solved if ever I am asked that question.

The simplest reference I keep to myself for that question is that it does not matter how long the string would be you will first check if the current item that you are on is a key in the hashmap/js-object and if so you will check the last added item if its saved as value in the object for that same key that means its a match, it's an open and close bracket and we will not push the current item to the stack or array and we will also pop that matched item from the stack/array since it will always be on the last index we will use pop method

const bracketMap = {
            "}":"{",
            "]":"[",
            ")":"("
        }

but let's say the current item is in the object but it did not have a match with last pushed item so that is return false immediately and break the loop. And the final part if the current item is not in the object as key that means we have an open bracket item that means we will do a push to the stack/array and we will keep doing it in the loop.

In the end we will just retun stack.length === 0 that is the requirement of the "Valid Parantheses" question only.

Stack has many more features to it and various usecases as well. I will definitely share what I understood and how I linked some of the code problems with real world things we interact with

[Solved] Appwrite user role missing or missing scope errors

Kaushal — Wed, 09 Oct 2024 01:30:49 +0000

Appwrite is awesome tool to use if you want to build applications fast but sometimes you may run into errors that can be frustrating and for me those errors were always about "User role missing" or "user not authorized to do this" etc. Even though I have full access to any instance of my app doing anything.

But finally I have found a way to fix them all (well maybe not all but i would like to think that).

So this discord post actually explained it in a very subtle way.

The catch is to make sure there is a session by using any of these methods I mean whichever you are using in your project.

createAnonymousSession
createEmailPasswordSession
createOAuth2Session
createSession

Let me give you an example where I faced this error then it might be more clear.

I had a signup page and what I want to do is as soon as user clicks on create account or signup it should trigger a verification email but I was getting the error that user is not authorized. The solution was to create a session before triggering the email so see the following code how I am creating session before triggering the email:

"use client";

import Link from "next/link";
import { FormEvent } from "react";
import { Button } from "@/components/ui/button";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { createAuthAccount } from "@/app/appwrite/createAuthAccount";
import { createLoginSession } from "@/app/appwrite/createLoginSession";
import { useRouter } from "next/navigation";
import { sendVerificationEmail } from "@/app/appwrite/sendVerificationEmail";

export const description =
  "A sign up form with first name, last name, email and password inside a card. There's an option to sign up with GitHub and a link to login if you already have an account";

export default function LoginForm() {
  const router = useRouter();
  const signUpFormHandler = async (event: FormEvent) => {
    event.preventDefault();
    const formData = new FormData(event.target as HTMLFormElement);
    const data = Object.fromEntries(formData.entries());
    const createdAccount = await createAuthAccount({
      email: data?.email.toString(),
      password: data?.password.toString(),
      name: data?.["full-name"].toString(),
    });
    if (createdAccount?.$id) {
      await createLoginSession({
        email: data?.email.toString(),
        password: data?.password.toString(),
      });
      await sendVerificationEmail();
    }
  };

  return (
    <Card className="mx-auto max-w-sm">
      <CardHeader>
        <CardTitle className="text-xl">Sign Up</CardTitle>
        <CardDescription>
          Enter your information to create an account
        </CardDescription>
      </CardHeader>
      <CardContent>
        <form onSubmit={signUpFormHandler} className="grid gap-4">
          <div className="grid gap-2">
            <Label htmlFor="full-name">Full name</Label>
            <Input name="full-name" id="full-name" placeholder="Max" required />
          </div>
          <div className="grid gap-2">
            <Label htmlFor="email">Email</Label>
            <Input
              id="email"
              type="email"
              placeholder="m@example.com"
              required
              name="email"
            />
          </div>
          <div className="grid gap-2">
            <Label htmlFor="password">Password</Label>
            <Input name="password" id="password" type="password" />
          </div>
          <Button type="submit" className="w-full">
            Create an account
          </Button>
        </form>
        <div className="mt-4 text-center text-sm">
          Already have an account?{" "}
          <Link href="#" className="underline">
            Sign in
          </Link>
        </div>
      </CardContent>
    </Card>
  );
}

This is just an example that depicts what was the intended behaviour and what was happening and what was suppose to be done.

Just wanted to share it in case any new beginners to Appwrite like me facing this error. All in all I have found that almost in all cases when I am getting any scope errors or user not authorized errors then creating a session or atleast making sure a session is existing before calling that method fixed those issues. So do give these a try and let me know what happens

SQL Databases for free on Cloud

Kaushal — Tue, 04 Jun 2024 02:36:20 +0000

There are many database providers out there but not all of them have free tier and even if they do sometimes its nothing useful. So less talking here is 5 free database hosting provider. I will just give the links here you can explore them on your own time to save u time reading this post

Render

TiDB or (PingCap)

Turso

Xata

Cockroach Labs

Thank you all and please share if you know any providers that are not very known or new

VS Code Extensions to have

Kaushal — Sun, 02 Jun 2024 19:58:06 +0000

I saw many posts showing what extensions one can have to improve their productivity and i thought lets share what I use too (except which are very common now like prettier, eslint, console ninja, etc), may be it will help people on top of what they already are using.

So here is a list of what extensions I use:

- Visual Studio Code Commitizen Support

It basically helps to write proper commit messages. With this extensions you can just press Mac: cmd + shift + p and windows: ctrl + shift + p and type commitizen and u will choose this option

after that just follow the steps and u will have a proper standardized commit message

- Sort Lines

Sometimes you need to have ur imports or exports in some alphabetical order either ascending or descending this extension will help you with that easily. Just select the lines you want sort and then just press Mac: cmd + shift + p and windows: ctrl + shift + p and type sort and u will see this

Choose which option you want and thats it.

- JSDoc Generator

Sometimes you just don't want to use the typescript or even if you are using it and want to describe your functions/components so anyone who is using them will know what a prop/param means or what the function is doing but don't want to write all that comments manually then this extension will help you with that.
Just go into the file which u want to generate the comments for and press Mac: cmd + shift + p and windows: ctrl + shift + p and type jsdoc and you will see this:

You can either choose the first option or the second option, most of the time i just use the second option and thats it you will have the proper syntax and everything generated u can ofcourse edit it more to make it more readable however u want but atleast it will do the initial work of writing comments for u

- Git Graph

This extension will help you visulize ur git and github branch graphs locally

Thank you and please do share your experience with these extensions
as well as the extensions you are using.