⚡ Concept first · Code second

Don't memorize DSA.
Live the story behind it.

Every question on CodeKatha begins with a story — a librarian, a treasure hunt, a queue outside a cinema — that plants the concept in your head before you write a single line of code. Then you solve real interview-style questions in a live compiler, watch your test cases pass, and let your streak grow. 🔥

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DSA questions (growing)
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The Librarian's Secret Register 📚

Meera the librarian never searches shelf-by-shelf. She keeps a register: book name → exact shelf number. One look, instant answer. That register, dear reader, is a hash map…

function twoSum(nums, target) { const seen = new Map(); // Meera's register for (let i = 0; i < nums.length; i++) { if (seen.has(target - nums[i])) return [seen.get(target - nums[i]), i]; seen.set(nums[i], i); } }
✔ Test 1 · [2,7,11,15], 9 → [0,1]
✔ Test 2 · [3,2,4], 6 → [1,2]
✔ Complexity: O(n) time · optimal ⚡

One question. Three acts.

You never see a question cold. The concept is built in your mind first — by hook or by crook — through stories, examples and analogies. Only then do you code.

01
📖

The Story

A short, vivid tale that hides the algorithm inside everyday life. By the end, you already understand the technique — you just don't know its scary name yet.

02
💡

The Concept

The story is decoded into the real concept: what it's called, when to use it, the time & space complexity, and the pattern to recognize it in interviews.

03
⚔️

The Battle

A real LeetCode/CodeChef-style question with a built-in compiler. Run your code, see test cases pass live ✅, and get your time & space complexity judged against the optimal.

🔥

Solve one a day. Keep the flame alive.

Your streak grows only when you solve at least one question that day — visiting isn't enough. Break the chain and the flame dies. Keep it burning and the rewards stack up:

🥉 30 days → Monthly Master + 500 XP 🥈 180 days → Half-Year Hero + 3000 XP 🥇 365 days → Yearly Legend + 10000 XP

Built to keep you hooked — on learning.

Everything in the client area is designed like a game, so the hours you'd waste scrolling go into building your interview muscle instead.

🧪

Live compiler in every question

JavaScript & Python. Run, see each test case pass or fail instantly, with inputs and expected outputs shown.

⏱️

Complexity checker

Your code's time & space complexity is estimated and compared with the optimal solution. O(n²) when O(n) exists? You'll know.

📈

Levels that unlock difficulty

Start with gentle beginner questions. As your level rises, harder questions unlock automatically.

🗓️

Streak heatmap

A GitHub-style calendar of your grind. Watching it fill up is dangerously addictive.

🏅

Badges & leaderboard

First Blood, Week Warrior, Centurion… earn them all and climb past other learners.

💬

Story-linked hints

Stuck? Hints don't spoil — they point back to the story: “remember the librarian's register?”

👑

Premium Pass

Less than a cup of chai. Forever.

₹9
  • Every premium question — medium, hard & expert sets
  • Complete story library + concept summaries
  • Full solution explanations after solving
  • Priority on the leaderboard with the 👑 crown
Register free, upgrade anytime

Pay via UPI → upload screenshot → approved by admin → confirmation mail. Simple.

Your first story is waiting.

Day 1 starts the moment you register. Free questions, free stories, free streak. The flame is yours to light. 🔥

Begin Chapter 1 →