LeetCode vs NeetCode vs AlgoExpert: The Ultimate Coding Interview Prep Guide

The Reality of Coding Interview Preparation

Let's be honest: coding interviews at top tech companies are hard. Really hard. But here's what most people get wrong—they either over-prepare for months without a strategy or under-prepare and hope for the best.

This guide will give you a clear comparison of the top platforms, realistic timelines for preparation, and if you're in a time crunch, the exact 20 questions you should practice if you only have 2 weeks.

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Platform Comparison: Which One Is Right for You?

LeetCode

The Industry Standard

| Aspect | Details |

|--------|---------|

| Problems | 3,000+ problems |

| Price | Free (Premium: $35/month or $159/year) |

| Best For | Comprehensive preparation, company-specific questions |

| Difficulty Curve | Steep—can feel overwhelming |

Pros:

• Largest problem database in the industry
• Company-tagged questions (Premium) show what Google, Meta, Amazon actually ask
• Active discussion forums with multiple solutions
• Weekly contests to test your skills under pressure
• SQL, Shell, and Concurrency problems beyond just algorithms

Cons:

• No structured learning path (can feel like drowning in problems)
• Quality of editorial solutions varies
• Premium required for the best features (company tags, frequency)
• Easy to waste time on obscure problems you'll never see

Verdict: Essential for serious preparation, but needs a structured approach to be effective.

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NeetCode

The Structured Alternative

| Aspect | Details |

|--------|---------|

| Problems | 150 curated (NeetCode 150) + 300 (NeetCode All) |

| Price | Free (videos) / Pro: $99 one-time |

| Best For | Beginners, structured learning, visual learners |

| Difficulty Curve | Gentle—builds concepts progressively |

Pros:

• Curated roadmap eliminates decision fatigue
• Excellent YouTube explanations for every problem
• Problems organized by pattern, not just difficulty
• NeetCode 150 is the gold standard for "enough" problems
• Clean UI that tracks your progress
• One-time payment (no subscription)

Cons:

• Smaller problem set than LeetCode
• Less company-specific data
• You'll still need LeetCode for actual practice
• Some advanced topics not covered

Verdict: Best starting point for most people. Use NeetCode's roadmap, but practice on LeetCode.

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AlgoExpert

The Premium Experience

| Aspect | Details |

|--------|---------|

| Problems | 200 curated problems |

| Price | $99/year (often bundled with SystemsExpert) |

| Best For | Those who prefer polished video content |

| Difficulty Curve | Moderate—well-paced |

Pros:

• High-quality video explanations
• Clean, distraction-free interface
• Includes behavioral interview prep
• Code execution in multiple languages
• Consistent quality across all problems

Cons:

• Smallest problem set of the three
• Expensive for what you get
• Less community engagement
• Problems don't match real interview frequency as well

Verdict: Good if you prefer premium content, but NeetCode offers similar quality for free.

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Other Notable Platforms

HackerRank

• Used by companies for actual screening tests
• Practice their environment before real assessments
• Free, but problems are less interview-focused

CodeSignal

• Another common screening platform
• General Coding Assessment (GCA) score used by many companies
• Worth practicing if a target company uses it

Interviewing.io

• Real mock interviews with engineers from top companies
• Expensive ($100-225 per session) but invaluable feedback
• Use after you've practiced problems, not before

Pramp

• Free peer mock interviews
• Good for practice, inconsistent partner quality
• Schedule at least 5-10 before real interviews

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Platform Comparison Table

| Feature | LeetCode | NeetCode | AlgoExpert | HackerRank |

|---------|----------|----------|------------|------------|

| Total Problems | 3,000+ | 150-300 | 200 | 1,000+ |

| Free Tier | Yes (limited) | Yes | No | Yes |

| Video Solutions | Some | All | All | Few |

| Company Tags | Yes (Premium) | No | No | No |

| Structured Path | No | Yes | Yes | Partial |

| Contest/Mock | Yes | No | No | Yes |

| Price | $159/yr | $99 once | $99/yr | Free |

| Best For | Depth | Structure | Quality | Screening |

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How Much Time Do You Really Need?

The Honest Timeline by Company Tier

Tier 1: FAANG+ (Google, Meta, Amazon, Apple, Netflix, Microsoft)

| Your Background | Recommended Time | Daily Commitment |

|----------------|------------------|------------------|

| New to DSA | 4-6 months | 2-3 hours/day |

| CS Graduate (rusty) | 2-3 months | 2-3 hours/day |

| Working Engineer | 6-8 weeks | 2-4 hours/day |

| Recent Interview Prep | 2-4 weeks | 3-4 hours/day |

Tier 2: High-Growth Tech (Stripe, Airbnb, Uber, LinkedIn)

| Your Background | Recommended Time | Daily Commitment |

|----------------|------------------|------------------|

| New to DSA | 3-4 months | 2 hours/day |

| CS Graduate (rusty) | 6-8 weeks | 2 hours/day |

| Working Engineer | 4-6 weeks | 2-3 hours/day |

Tier 3: Solid Tech Companies (Most Series B+ Startups)

| Your Background | Recommended Time | Daily Commitment |

|----------------|------------------|------------------|

| New to DSA | 2-3 months | 1-2 hours/day |

| CS Graduate (rusty) | 4-6 weeks | 1-2 hours/day |

| Working Engineer | 2-4 weeks | 1-2 hours/day |

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The Study Plan by Timeline

6 Months Out (Comprehensive)

• Weeks 1-4: Learn/review all data structures
• Weeks 5-8: Learn all algorithm patterns
• Weeks 9-16: NeetCode 150 (all problems)
• Weeks 17-20: Company-specific LeetCode problems
• Weeks 21-24: Mock interviews + review weak areas

3 Months Out (Focused)

• Weeks 1-2: Rapid data structure review
• Weeks 3-8: NeetCode 150 (prioritize mediums)
• Weeks 9-10: Company-tagged problems
• Weeks 11-12: Mock interviews + weak areas

6 Weeks Out (Accelerated)

• Week 1: Core data structures (arrays, strings, hashmaps)
• Weeks 2-3: Core patterns (two pointers, sliding window, BFS/DFS)
• Weeks 4-5: NeetCode 75 (curated subset)
• Week 6: Mock interviews + company problems

2 Weeks Out (Emergency Mode)

• See the "Top 20 Questions" section below

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The Top 20 LeetCode Questions for 2-Week Prep

If you only have 2 weeks before your interview, focus on these 20 problems. They cover the most common patterns and have the highest ROI for your time.

Week 1: Foundations (Problems 1-10)

Day 1-2: Arrays & Hashing

• **Two Sum** (Easy) - LeetCode #1
• Pattern: Hash map lookup
• Why: Asked everywhere, tests basic problem-solving
• Key insight: Trade space for time with a hash map

• **Best Time to Buy and Sell Stock** (Easy) - LeetCode #121
• Pattern: Track minimum while iterating
• Why: Classic interview question, tests greedy thinking
• Key insight: Track min price seen so far, calculate max profit at each step

• **Contains Duplicate** (Easy) - LeetCode #217
• Pattern: Hash set for O(1) lookup
• Why: Warm-up problem, often asked as a screener
• Key insight: Set lookup is O(1)

Day 3-4: Two Pointers & Sliding Window

• **Valid Palindrome** (Easy) - LeetCode #125
• Pattern: Two pointers from ends
• Why: String manipulation basics
• Key insight: Skip non-alphanumeric, compare lowercase

• **3Sum** (Medium) - LeetCode #15
• Pattern: Sort + two pointers
• Why: Extremely common, tests multiple concepts
• Key insight: Fix one number, use two pointers for the rest

• **Longest Substring Without Repeating Characters** (Medium) - LeetCode #3
• Pattern: Sliding window with hash set
• Why: Classic sliding window, asked at every major company
• Key insight: Expand right, shrink left when duplicate found

Day 5-6: Linked Lists

• **Reverse Linked List** (Easy) - LeetCode #206
• Pattern: Three-pointer iteration
• Why: Fundamental linked list operation
• Key insight: prev, curr, next pointers

• **Merge Two Sorted Lists** (Easy) - LeetCode #21
• Pattern: Dummy head + iteration
• Why: Common building block for harder problems
• Key insight: Dummy node simplifies edge cases

• **Linked List Cycle** (Easy) - LeetCode #141
• Pattern: Fast and slow pointers
• Why: Tests Floyd's algorithm knowledge
• Key insight: Fast moves 2x, slow moves 1x

Day 7: Review + Binary Search

• **Binary Search** (Easy) - LeetCode #704
• Pattern: Classic binary search
• Why: Foundation for many medium/hard problems
• Key insight: left <= right, mid calculation to avoid overflow

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Week 2: Intermediate Patterns (Problems 11-20)

Day 8-9: Trees

• **Invert Binary Tree** (Easy) - LeetCode #226
• Pattern: Recursive tree traversal
• Why: Tests recursion basics
• Key insight: Swap left and right, recurse

• **Maximum Depth of Binary Tree** (Easy) - LeetCode #104
• Pattern: DFS recursion
• Why: Foundation for tree problems
• Key insight: 1 + max(left depth, right depth)

• **Validate Binary Search Tree** (Medium) - LeetCode #98
• Pattern: DFS with valid range
• Why: Tests BST property understanding
• Key insight: Pass min/max bounds down the tree

• **Lowest Common Ancestor of BST** (Medium) - LeetCode #235
• Pattern: BST traversal
• Why: Common tree question
• Key insight: Use BST property—if both less, go left; both greater, go right

Day 10-11: Graphs & BFS/DFS

• **Number of Islands** (Medium) - LeetCode #200
• Pattern: DFS/BFS grid traversal
• Why: Classic graph problem, asked constantly
• Key insight: DFS from each '1', mark visited as '0'

• **Clone Graph** (Medium) - LeetCode #133
• Pattern: BFS/DFS with hash map
• Why: Tests graph traversal + data structure creation
• Key insight: HashMap from old node to new node

Day 12-13: Dynamic Programming

• **Climbing Stairs** (Easy) - LeetCode #70
• Pattern: Basic DP (Fibonacci variant)
• Why: DP introduction
• Key insight: dp[i] = dp[i-1] + dp[i-2]

• **House Robber** (Medium) - LeetCode #198
• Pattern: 1D DP with decision
• Why: Classic DP pattern
• Key insight: dp[i] = max(dp[i-1], dp[i-2] + nums[i])

• **Coin Change** (Medium) - LeetCode #322
• Pattern: Unbounded knapsack DP
• Why: Tests DP thinking
• Key insight: dp[amount] = min(dp[amount], dp[amount-coin] + 1)

Day 14: Heap + Review

• **Kth Largest Element in an Array** (Medium) - LeetCode #215
• Pattern: Min heap of size k / Quickselect
• Why: Tests heap knowledge or partition algorithm
• Key insight: Keep heap of size k, root is answer

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2-Week Study Schedule

| Day | Morning (1.5 hrs) | Evening (1.5 hrs) |

|-----|-------------------|-------------------|

| 1 | Two Sum, Contains Duplicate | Review solutions, understand patterns |

| 2 | Best Time to Buy/Sell Stock | Practice variations |

| 3 | Valid Palindrome, 3Sum | Two pointer pattern review |

| 4 | Longest Substring Without Repeating | Sliding window pattern review |

| 5 | Reverse Linked List, Merge Two Lists | Linked list pattern review |

| 6 | Linked List Cycle | Review all Week 1 problems |

| 7 | Binary Search + Week 1 Review | Mock interview (Pramp) |

| 8 | Invert Tree, Max Depth | Tree recursion pattern |

| 9 | Validate BST, LCA of BST | BST property problems |

| 10 | Number of Islands | BFS/DFS grid review |

| 11 | Clone Graph | Graph pattern review |

| 12 | Climbing Stairs, House Robber | DP pattern introduction |

| 13 | Coin Change | DP pattern deep dive |

| 14 | Kth Largest + Full Review | Mock interview (Pramp) |

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Pattern Recognition Cheat Sheet

Memorize these patterns—they cover 90% of interview questions:

| Pattern | When to Use | Key Problems |

|---------|-------------|--------------|

| Hash Map | O(1) lookup needed, counting | Two Sum, Group Anagrams |

| Two Pointers | Sorted array, palindrome | 3Sum, Container With Water |

| Sliding Window | Subarray/substring problems | Longest Substring, Min Window |

| Fast & Slow | Cycle detection, middle element | Linked List Cycle, Happy Number |

| Binary Search | Sorted array, search space | Search in Rotated, Koko Eating |

| BFS | Shortest path, level order | Number of Islands, Word Ladder |

| DFS | Explore all paths, backtracking | Permutations, Subsets |

| DP | Optimal substructure, overlapping | Coin Change, Longest Subsequence |

| Heap | K-th element, streaming data | Kth Largest, Merge K Lists |

| Stack | Matching pairs, monotonic | Valid Parentheses, Daily Temps |

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Company-Specific Insights

Google

• Focuses on problem-solving process over correct answer
• Expect follow-up questions and optimizations
• Strong emphasis on time/space complexity analysis
• Prepare: Graph problems, DP, system design

Amazon

• Leadership Principles matter as much as coding
• Often asks medium difficulty, expects clean code
• May ask 2 coding questions in one round
• Prepare: BFS/DFS, OOP design, LP stories

Meta (Facebook)

• 45-minute rounds, expects working solution in 25-30 mins
• Communication is heavily weighted
• Product sense matters for senior roles
• Prepare: Trees, graphs, string manipulation

Microsoft

• More traditional CS questions
• May include system design earlier than other companies
• Culture fit matters
• Prepare: Arrays, trees, basic DP

Apple

• Domain-specific questions possible (iOS/macOS)
• Emphasis on code quality and design
• Smaller team fit interviews
• Prepare: Standard patterns + domain knowledge

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Common Mistakes to Avoid

1. **Grinding without understanding** — Solving 500 problems poorly is worse than solving 100 deeply

1. **Skipping the explanation** — Always articulate your thought process out loud

1. **Not timing yourself** — Practice under realistic time pressure (25-35 mins per medium)

1. **Ignoring edge cases** — Empty input, single element, duplicates, negative numbers

1. **Memorizing solutions** — Understand patterns, don't memorize code

1. **Only practicing easy problems** — Interviews are mostly medium, some hard

1. **Not doing mock interviews** — Talking while coding is a skill that needs practice

1. **Neglecting system design** — Required for senior roles, start early

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Your Action Plan

Starting Today:

1. Take a LeetCode assessment to gauge your level
2. Pick your timeline based on target companies
3. Create a study schedule you can actually stick to
4. Join the NeetCode Discord for accountability

This Week:

1. Set up accounts on LeetCode and NeetCode
2. Complete the first 5 problems from the Top 20 list
3. Schedule your first Pramp mock interview for next week

Ongoing:

1. Track your progress (problems solved, patterns mastered)
2. Review wrong answers—they teach more than correct ones
3. Do at least 2 mock interviews before the real thing

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Final Thoughts

Coding interviews are a skill, and like any skill, they can be learned. The engineers who succeed aren't necessarily the smartest—they're the ones who prepared systematically and practiced deliberately.

Whether you have 6 months or 2 weeks, focus on understanding patterns over memorizing solutions. Every problem you truly understand makes the next ten easier.

Your dream job at a top tech company is achievable. Start today, stay consistent, and trust the process.

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Pair Your Technical Prep with a Strong Resume

Technical skills get you through the coding interview, but your resume gets you the interview in the first place. IdealResume helps you:

• Highlight your technical projects and achievements
• Optimize for ATS systems at top tech companies
• Tailor your experience to specific job descriptions

Don't let a weak resume hold you back from showcasing your hard-earned coding skills.