You know the patterns. You understand complexity analysis. You can discuss trade-offs. But none of that matters if your preparation is scattered, if you spend three weeks on trees and zero on graphs, if you never do a mock interview, or if you burn out two weeks before the actual date.

A study plan is not optional. It is the difference between "I studied for three months" and "I prepared effectively for three months." This chapter gives you concrete, week-by-week schedules for 1-month, 2-month, and 3-month timelines. Not vague advice like "practice LeetCode." Specific numbers, specific topics, specific daily routines.

Pick the timeline that matches your schedule, and follow it.

Three factors determine which plan is right for you:

Not all topics appear equally often. Spend more time on high-frequency topics and less on rare ones. This ranking is based on patterns from thousands of interview questions across FAANG and top companies.

Tier 1 and Tier 2 cover roughly 80% of interview questions. If time is limited, do not touch Tier 4 until Tier 1 and 2 are solid.

This plan is for developers who already know data structures and have some problem-solving experience. You are refreshing and sharpening, not learning from scratch.

Daily structure: 3-4 hours

Week 1: Core Patterns (Tier 1)

Problems per day: 3-5 Total for week: ~25-30

Week 2: Intermediate Patterns (Tier 1-2)

Problems per day: 3-5 Total for week: ~25-30

Week 3: Advanced + Weak Areas (Tier 2-3)

Week 4: Mocks and Polish

Total problems over 4 weeks: ~100-120

More breathing room. You can learn patterns properly, practice each one with enough problems to build intuition, and still have time for mocks.

Daily structure: 2-3 hours

Weeks 1-2: Foundations

Spend extra time understanding each pattern before solving. Read the pattern explanation, study 1-2 solved examples, then solve on your own.

Weeks 3-4: Core Data Structures

Weeks 5-6: Advanced Patterns

These topics are harder. Reduce problem count and increase study time per problem. For DP especially, spend 10-15 minutes understanding the recurrence before coding.

Weeks 7-8: Mocks and Company Prep

Total problems over 8 weeks: ~140-160

This is the plan for people who are learning many patterns for the first time or have been away from DSA for years. The pace is sustainable, and there is time to truly internalize each pattern.

Daily structure: 1.5-2 hours

Month 1: Learn Patterns (Weeks 1-4)

Weekly total: ~14 problems Month total: ~55 problems

Month 2: Practice and Deepen (Weeks 5-8)

Weekly total: ~15 problems Month total: ~60 problems

Month 3: Mock Interviews and Polish (Weeks 9-12)

Monthly total: ~50 problems Grand total over 3 months: ~165 problems

Whatever timeline you choose, your daily session should follow this structure:

The review phase is where learning actually happens. Solving a problem teaches you one thing. Understanding why the solution works teaches you the pattern you can apply to fifty other problems.

If you have been staring at a problem for 20 minutes with no progress, stop trying and look at a hint or the approach description. Here is why:

After reading the hint or approach, close it and implement the solution yourself. That is the critical step. Reading a solution is passive. Implementing it is active learning.

A topic is "done" when you can:

If you cannot do all four, you need more practice on that topic. If you can, move on even if you have not solved every problem on the list. Breadth of patterns matters more than depth on a single pattern.

Start mocks when you have covered at least Tier 1 and Tier 2 topics. For the 1-month plan, that means week 3. For the 2-month plan, week 6. For the 3-month plan, week 9.

Do not wait until you feel "ready." You will never feel ready. Mocks expose gaps that solo practice cannot:

Aim for at least 4-6 mock interviews before your real ones. Use a friend, a study partner, or platforms like Pramp or interviewing.io.

Keep a simple spreadsheet or document with these columns:

The "Redo?" column is the most important one. Every Sunday, revisit problems marked "Yes." If you can solve them cleanly now, remove the mark. If not, they stay on the redo list. This spaced repetition is how patterns move from short-term to long-term memory.

A common mistake is spending all your time learning new patterns without practicing old ones. Another common mistake is grinding problems without learning the underlying pattern first. The right balance:

This means if you have a 2-hour session, spend roughly 80 minutes on today's problems, 25 minutes reviewing past problems, and 15 minutes reading about tomorrow's topic.

The final 7 days are not for learning new material. They are for consolidation and confidence.

Q1: You have exactly 6 weeks to prepare and can dedicate 2 hours per day. How would you allocate your time across topics?

Weeks 1-2 on Tier 1 topics (arrays, hashing, two pointers, sliding window, binary search) with 3 problems per day. Weeks 3-4 on Tier 2 topics (trees, graphs, heaps, stacks, 1D DP) with 2-3 problems per day. Week 5 on Tier 3 topics (2D DP, backtracking, tries) and mixed practice. Week 6 on mock interviews and company-tagged problems. This gives roughly 120 problems with emphasis on the highest-frequency patterns.

Q2: How do you decide whether to keep practicing a topic or move on?

Move on when you can: explain the pattern in one sentence, identify it from a problem description, solve a medium in under 30 minutes, and handle variations. If you fail any of those criteria, do 2-3 more problems on that topic. Do not aim for perfection. Covering more patterns has higher return than mastering one.

Q3: What is more valuable, solving 300 easy problems or 100 problems across all difficulties?

100 problems across all difficulties. Easy problems rarely appear in interviews, and they do not build the reasoning skills needed for mediums and hards. Use easys (2-3 per topic) to understand the basic pattern, then move to mediums. Hards are important for top-tier companies but should make up only 10-15% of your practice.

This plan is a starting point. Adjust it as you discover your specific weaknesses. The goal is not to follow a rigid schedule. The goal is to make consistent, measurable progress every week until interview day.