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AlgoBook

AI-verified interview practice with a LeetCode-parity editor, an AI tutor and a rating — in Java, Python, C++ and JavaScript.

Built by CognitiveSquad · India

Product

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  • Live demo
  • Pricing
  • vs LeetCode
  • FAQ

Practice

  • Explore problems
  • Daily challenge
  • Leaderboard
  • Mock interview

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© 2026 AlgoBook. All rights reserved.

Prices in INR. Pro renews manually — no auto-deduction.

Every problem verified on the judge before you see it

Practice like it’s the real interview.

AI-generated, judge-verified problems in Java, Python, C++ and JavaScript. A LeetCode-parity editor, an AI tutor that won’t spoil the answer, spaced repetition, a rating and a daily challenge — planned around your goal.

Start free See a problemNo credit card. Google sign-in.
Problems verified
0
Solves today
0
Languages
0
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Company lists modelled on

  • Google
  • Amazon
  • Meta
  • Microsoft
  • Apple
  • Uber

Live demo

This is the actual workspace. Run something.

Edit the code and press Run — it executes against the sample tests right here, no account needed. Sign in for hidden tests, Java/Python/C++, Beats % and the tutor.

Problem List
Submit
⌘' to run
Description

1. Two Sum

EasyArrayHash Map

Given an array of integers nums and an integer target, return the indices of the two numbers such that they add up to target.

You may assume that each input has exactly one solution, and you may not use the same element twice. Return the answer in any order.

Example 1:

Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Explanation: nums[0] + nums[1] == 9.

Example 2:

Input: nums = [3,2,4], target = 6
Output: [1,2]

Example 3:

Input: nums = [3,3], target = 6
Output: [0,1]

Constraints:

  • 2 ≤ nums.length ≤ 10⁴
  • −10⁹ ≤ nums[i] ≤ 10⁹
  • Only one valid answer exists.

Follow-up: Can you do it in O(n) time?

CodeJavaScript Java · Python · C++ after sign-in
/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
function twoSum(nums, target) {
  // Try a hash map: value -> index
  
}
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2
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nums =

[2,7,11,15]

target =

9
Stuck? Open the full workspace

What you get

More capable than a static problem list — and honest about it.

Verified before you see it

A reference solution runs against every hidden test on the judge at generation time. Broken drivers — the #1 complaint about AI problem sets — cannot reach your editor.

Verified before you see it — product screenshot

LeetCode-parity editor

Resizable panels, testcases with named parameters, Beats %, editorial, submissions, notes, timer, Vim/Emacs, ⌘' to run.

Hints, editorial, tutor

Three hint levels, an editorial in every language, error explanations and a scoped tutor chat that refuses to hand over the solution.

Mastery + spaced repetition

Topic mastery from accuracy, first-try rate, speed and independence; SM-2 review scheduling brings weak topics back at the right time.

Mastery + spaced repetition — product screenshot

Company templates

Google, Amazon, Meta, Microsoft, Apple and Uber lists, pre-generated and verified in all four languages.

Rating & leaderboard

An Elo-style rating per solve, global and weekly boards, and company cohorts.

Daily challenge

One verified problem for everyone every day; +20 XP and a streak that survives a missed day with a freeze.

Mock interview

45 minutes, two problems around your rating, no hints — then an AI interviewer debriefs you: score, verdict, strengths, gaps.

How it works

Three steps. No busywork.

  1. Week 1 · Arrays, Hash map
    Week 2 · Two pointers, Sliding window
    Week 3 · Trees, BFS/DFS

    01

    Describe your goal

    Pick a company template or tell us the role, the date and the topics you dread. AlgoBook AI writes a plan with milestones and a weekly focus.

  2. Generate
    Reference solution
    14 hidden tests
    Verified ✓

    02

    Solve verified problems

    Each problem is generated for you or reused from the shared pool, executed against hidden tests and only then served — with hints, editorial and a tutor on tap.

  3. 03

    Track, adapt, repeat

    Mastery, spaced repetition and your rating decide what comes next. Streaks, XP, badges and boards keep you coming back.

Compared

AlgoBook vs LeetCode

LeetCode is the benchmark — our editor deliberately matches it. Where we differ is everything around the problem.

FeatureAlgoBookLeetCode
Personalised problem generation around your goal
Every problem executed against hidden tests before it is servedCurated by staff
AI tutor that explains errors and hints without spoilingLimited
Editorial for every problem in 4 languagesPremium, selected problems
Spaced repetition & topic mastery
Rating per solve, weekly boards, company cohortsContests only
Mock interview with AI debriefProPremium, separate
PriceFree · Pro ₹499/moPremium ≈ ₹2,900/mo

LeetCode pricing and features as publicly listed on 2026-09-07; verify current terms on their site.

Pricing

Simple, transparent pricing

Full access. No auto-deduction. Renew only when you want to.

Free

₹0forever

Daily practice from the verified pool with a taste of generation.

Start free

No credit card

Most popular

Pro Monthly

₹499/ 30 days

Everything unlocked. Ideal for a focused interview sprint.

Go Pro

No auto-renewal · renew manually

Save 17%

Pro Yearly

₹4,999/ year

Save 17% — a full year of uninterrupted access.

Go Pro yearly

No auto-renewal · renew manually

Daily limitsFreePro
AI-generated problems / day3200
Verified pool problemsUnlimitedUnlimited
Runs / day302,000
Languages (Java · Python · C++ · JS)All 4All 4
HintsLevels 1–2Levels 1–3 (reads your code)
EditorialsUnlimited
AI tutor chat300 msgs / day
Inline AI completion3,000 / day
Post-solve code review200 / day
Mock interviews5 / day
Daily challenge, streaks, leaderboardIncludedIncluded

FAQ

Questions, answered

Ready when you are.

Your first project takes two minutes. Your first accepted solution, maybe five.

Start free