W Code - Pattern-Based DSA Learning Platform

Bhanu Bisht

Curated List

Top Stack Patterns Problems for Coding Interviews

Master the Stack Patterns pattern with this curated list of 11 must-solve problems. Each problem is ranked by interview frequency, difficulty, and learning value. LIFO-based solutions for parsing, matching, and evaluation.

Ranking Criteria: Interview frequency (40%), Learning value (30%), Difficulty progression (20%), Company tag count (10%).

Ranking Methodology

We rank Stack Patterns problems using four criteria:

1.Interview Frequency (40%) — How often the problem appears in real interviews (Google, Amazon, Microsoft, etc.)

2.Learning Value (30%) — Whether solving it teaches transferable concepts

3.Difficulty Progression (20%) — Problems ordered from Easy → Medium → Hard for systematic learning

4.Company Coverage (10%) — Number of companies that actively ask this problem

Must-Solve Problems (Easy)

3 easy problems focusing on basic pattern recognition and implementation.

Pro tip: Solve these first to build confidence. Target: 15 minutes each.

Practice all Easy Stack Patterns problems on W Code with instant feedback and solution explanations.

Core Problems (Medium)

6 medium problems focusing on combining the pattern with other techniques.

Pro tip: These form the core of your interview prep. Target: 25 minutes each.

Practice all Medium Stack Patterns problems on W Code with instant feedback and solution explanations.

Advanced Problems (Hard)

3 hard problems focusing on complex variations and optimization.

Pro tip: Only attempt after mastering Medium. Target: 40 minutes with hints if needed.

Practice all Hard Stack Patterns problems on W Code with instant feedback and solution explanations.

Study Plan

Week 1: Solve all Easy problems to build pattern recognition

Week 2: Tackle Medium problems — aim for 2-3 per day

Week 3: Attempt Hard problems with 45-minute timer

Week 4: Re-solve problems you struggled with

Daily target: 2 problems minimum, 4 maximum (quality over quantity).

Use the Stack Patterns template from W Code to develop muscle memory for the pattern structure.

Tips for ${pattern.name} Problems

1.Always identify the pattern before jumping into code

2.Start with brute force, then optimize to O(n)

3.Practice explaining your approach out loud

4.Test with edge cases: empty input, single element, large n

5.Time yourself — aim for 20 minutes on Medium problems

Frequently Asked Questions

How many Stack Patterns problems should I solve?

Solve at least 10 problems to build strong pattern recognition. For FAANG prep, aim for all 11.

Which companies ask Stack Patterns questions?

Google, Amazon, Microsoft, and Meta frequently ask Stack Patterns problems. Service companies like TCS and Infosys test simpler variations.

What should I learn before Stack Patterns?

Prerequisites: Arrays basics. Make sure you're comfortable with these first.

Practice all 11 Stack Patterns problems with AI hints and step-by-step solutions on W Code. Start free!

Start Learning Free

Loading W Code...

Curated List