LeetCode Guide

The key to mastering LeetCode is understanding and practicing common coding patterns. By focusing on these patterns, you will be able to solve a wider range of problems more effectively.

I solve LeetCode problems and explain the patterns on my TikTok account @GarciaCoding.

Study Tips & Strategy

🎯 The 3-Step Approach

  1. First 25 minutes: Try to solve without help
  2. Next 15 minutes: Look at hints or similar problems
  3. If still stuck: Study the solution and understand every line

📚 Study Plan

  • Start with Easy problems in each pattern
  • Aim to solve 2-3 problems daily
  • Review and retry problems after a week
  • Keep a coding journal for patterns and insights

Time Complexity Quick Reference

Common Operations

  • Array/String Access: O(1)
  • Array/String Search: O(n)
  • Sorting: O(n log n)
  • Hash Table Access/Insert: O(1)

Space Complexity Tips

  • In-place modification: O(1)
  • Recursion stack: O(h) - height
  • Hash map of n items: O(n)
  • Creating new array: O(n)

Interview Success Tips

Before Coding

  • Clarify requirements and edge cases
  • Discuss multiple approaches
  • Explain time/space complexity
  • Use examples to verify understanding

While Coding

  • Think aloud - explain your thought process
  • Write clean, organized code
  • Handle edge cases explicitly
  • Test your solution with examples

Track Your Progress

Keep track of your progress by following these milestones:

Beginner Milestones

  • Complete all Easy HashMap problems
  • Solve Array/String basics
  • Master Basic Recursion

Intermediate Goals

  • Complete Medium DFS/BFS problems
  • Master Sliding Window technique
  • Solve Dynamic Programming basics

Advanced Challenges

  • Tackle Hard problems in each category
  • Optimize solutions for space/time
  • Solve problems under time constraints

Ready to Practice?

Now that you understand the strategies and patterns, start practicing with our curated list of problems.

View Problems by Pattern →