Decoded — a simple way to actually understand DSA

Sreya Satheesh — Mon, 13 Apr 2026 06:35:09 +0000

👉https://decoded-app.vercel.app/

When you're learning DSA, there’s a point where things start feeling repetitive.

You solve problems.
You look at solutions.
You understand them.

But a few days later, the same type of problem feels new again.

That usually happens because you're remembering solutions, not the thinking behind them.

Decoded is a small web app built to fix that.

What Decoded tries to do

The goal is pretty simple:

Make it easier to understand how to approach problems — not just how to code the solution.

Instead of dumping answers, it focuses on:

breaking problems down
showing how the solution evolves
helping you recognize patterns

Inside the app

Problems with step-by-step thinking

Each problem comes with:

a clear explanation
a structured approach
a step-by-step dry run

The dry run is the important part.

You can actually follow:

how variables change
how pointers move
how the solution builds up

So you can see everything happen instead of imagining it.

Complexity

Every solution includes:

time complexity
space complexity

But instead of just stating Big-O, the focus is on why it’s that value.

Patterns

One of the most useful sections is the Patterns page.

A lot of DSA problems aren’t unique — they’re variations of a few common ideas.

This page groups problems based on patterns like:

two pointers
sliding window
prefix sum

Each pattern explains:

how it works
when to use it
what kind of problems it fits

Over time, you stop thinking “I’ve seen this before”
and start thinking “this looks like a sliding window problem.”

That’s a big difference.

Data Structures

The Data Structures page focuses on fundamentals.

It covers things like:

arrays
linked lists
stacks
queues

The idea isn’t to go deep into theory, but to keep it practical.

Each structure is explained in terms of:

what it does
how it behaves

So instead of just knowing definitions, you start understanding when to use what.

Who this is for

beginners starting DSA
people preparing for interviews

DEV Community: Sreya Satheesh