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skills/leetcode-teacher/SKILL.md
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skills/leetcode-teacher/SKILL.md
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---
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name: leetcode-teacher
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description: Interactive LeetCode-style teacher for technical interview preparation. Generates coding playgrounds with real product challenges, teaches patterns and techniques, supports Python/TypeScript/Kotlin/Swift, and provides progressive difficulty training for data structures and algorithms.
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---
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# LeetCode Teacher
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An interactive technical interview preparation teacher that generates engaging coding playgrounds with real-world product challenges, pattern recognition training, and multi-language support.
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## What This Skill Does
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Transforms technical interview prep into interactive, practical experiences:
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- **Interactive Code Playgrounds** - Browser-based coding environments with instant feedback
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- **Multi-Language Support** - Python, TypeScript, Kotlin, Swift
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- **Real Product Challenges** - Practical scenarios from real companies
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- **Pattern Recognition** - Learn the 20 essential coding patterns
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- **Progressive Difficulty** - Easy → Medium → Hard → Expert
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- **Instant Feedback** - Run tests in real-time with detailed explanations
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- **Technique Teaching** - Master problem-solving approaches
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## Why This Skill Matters
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**Traditional LeetCode practice:**
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- Abstract, disconnected problems
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- No pattern recognition guidance
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- Trial and error approach
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- Intimidating for beginners
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- Limited language options
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**With this skill:**
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- Real product scenarios
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- Pattern-based learning
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- Guided problem-solving
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- Progressive difficulty curve
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- Multi-language practice
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- Interactive, fun interface
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## Core Principles
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### 1. Pattern-First Learning
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- Recognize problem patterns
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- Apply proven templates
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- Build intuition through practice
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- Master one pattern at a time
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### 2. Real Product Context
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- Instagram feed ranking
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- Uber trip matching
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- Netflix recommendation
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- Slack message search
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- Amazon inventory management
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### 3. Progressive Difficulty
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- Start with fundamentals
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- Build complexity gradually
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- Unlock advanced patterns
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- Track skill progression
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### 4. Multi-Language Mastery
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- Practice in your target language
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- Compare implementations
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- Learn language-specific tricks
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- Interview in any language
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### 5. Interactive Learning
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- Write code in browser
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- Run tests instantly
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- Get hints when stuck
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- See optimal solutions
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- Track progress
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## Problem Patterns Covered
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### Array & String Patterns
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**1. Two Pointers**
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```
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Pattern: Use two pointers to scan array
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Use when: Need to find pairs, triplets, or subarrays
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Example: "Find Instagram users who like each other"
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Complexity: O(n) time, O(1) space
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```
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**2. Sliding Window**
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```
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Pattern: Maintain a window that slides through array
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Use when: Need to find subarray with certain property
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Example: "Find trending topics in last N tweets"
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Complexity: O(n) time, O(k) space
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```
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**3. Fast & Slow Pointers**
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```
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Pattern: Two pointers moving at different speeds
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Use when: Detect cycles, find middle element
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Example: "Detect circular dependency in package manager"
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Complexity: O(n) time, O(1) space
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```
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### Tree & Graph Patterns
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**4. Tree BFS**
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```
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Pattern: Level-order traversal using queue
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Use when: Need level-by-level processing
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Example: "Show friends by degree of connection"
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Complexity: O(n) time, O(w) space (w = max width)
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```
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**5. Tree DFS**
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```
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Pattern: Preorder, inorder, or postorder traversal
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Use when: Need to explore all paths
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Example: "Find all paths in file system"
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Complexity: O(n) time, O(h) space (h = height)
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```
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**6. Graph BFS**
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```
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Pattern: Explore neighbors level by level
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Use when: Shortest path, level-based exploration
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Example: "Find shortest connection path on LinkedIn"
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Complexity: O(V + E) time, O(V) space
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```
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**7. Graph DFS**
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```
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Pattern: Explore as far as possible before backtracking
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Use when: Path finding, cycle detection
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Example: "Detect circular references in social graph"
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Complexity: O(V + E) time, O(V) space
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```
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**8. Topological Sort**
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```
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Pattern: Order nodes by dependencies
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Use when: Task scheduling, build systems
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Example: "Order courses based on prerequisites"
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Complexity: O(V + E) time, O(V) space
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```
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### Dynamic Programming Patterns
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**9. 0/1 Knapsack**
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```
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Pattern: Include or exclude each item
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Use when: Optimization with constraints
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Example: "Select best ads within budget"
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Complexity: O(n * capacity) time and space
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```
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**10. Unbounded Knapsack**
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```
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Pattern: Can use item unlimited times
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Use when: Coin change, combinations
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Example: "Minimum transactions to reach balance"
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Complexity: O(n * target) time and space
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```
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**11. Fibonacci Numbers**
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```
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Pattern: Current state depends on previous states
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Use when: Climbing stairs, tiling problems
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Example: "Ways to navigate through app screens"
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Complexity: O(n) time, O(1) space optimized
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```
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**12. Longest Common Subsequence**
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```
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Pattern: Compare two sequences
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Use when: Diff tools, edit distance
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Example: "Find similar code snippets"
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Complexity: O(m * n) time and space
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```
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### Other Essential Patterns
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**13. Modified Binary Search**
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```
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Pattern: Binary search on sorted or rotated array
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Use when: Search in O(log n)
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Example: "Find version when bug was introduced"
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Complexity: O(log n) time, O(1) space
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```
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**14. Top K Elements**
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```
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Pattern: Use heap to track K largest/smallest
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Use when: Finding top items
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Example: "Get top K trending hashtags"
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Complexity: O(n log k) time, O(k) space
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```
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**15. K-Way Merge**
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```
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Pattern: Merge K sorted arrays/lists
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Use when: Combining sorted data
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Example: "Merge activity feeds from K users"
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Complexity: O(n log k) time, O(k) space
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```
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**16. Backtracking**
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```
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Pattern: Try all possibilities with pruning
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Use when: Generate permutations, combinations
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Example: "Generate all valid parentheses combinations"
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Complexity: Varies, often exponential
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```
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**17. Union Find**
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```
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Pattern: Track connected components
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Use when: Network connectivity, grouping
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Example: "Find connected friend groups"
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Complexity: O(α(n)) amortized per operation
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```
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**18. Intervals**
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```
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Pattern: Merge, insert, or find overlapping intervals
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Use when: Calendar scheduling, time ranges
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Example: "Find free meeting slots"
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Complexity: O(n log n) time, O(n) space
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```
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**19. Monotonic Stack**
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```
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Pattern: Maintain increasing/decreasing stack
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Use when: Next greater/smaller element
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Example: "Stock price span calculation"
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Complexity: O(n) time, O(n) space
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```
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**20. Trie**
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```
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Pattern: Prefix tree for string operations
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Use when: Autocomplete, prefix matching
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Example: "Implement search autocomplete"
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Complexity: O(m) time per operation (m = word length)
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```
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## Real Product Challenge Examples
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### Easy Level
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**Instagram: Like Counter**
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```
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Real Scenario: Count how many times user's posts were liked today
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Pattern: Hash Map
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Data Structure: Dictionary/HashMap
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Languages: Python, TypeScript, Kotlin, Swift
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```
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**Slack: Unread Messages**
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```
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Real Scenario: Find first unread message in channel
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Pattern: Linear Search with Flag
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Data Structure: Array
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Teaches: Early termination
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```
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**Uber: Calculate Fare**
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```
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Real Scenario: Compute trip cost based on distance and time
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Pattern: Simple Calculation
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Data Structure: Numbers
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Teaches: Math operations, rounding
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```
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### Medium Level
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**Netflix: Top N Recommendations**
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```
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Real Scenario: Find top N movies by rating
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Pattern: Top K Elements (Heap)
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Data Structure: Priority Queue
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Teaches: Heap operations, partial sorting
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```
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**Amazon: Inventory Management**
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```
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Real Scenario: Find products running low in stock
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Pattern: Filtering with Threshold
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Data Structure: Array + HashMap
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Teaches: Multi-criteria filtering
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```
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**Twitter: Trending Hashtags**
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```
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Real Scenario: Find most used hashtags in time window
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Pattern: Sliding Window + Frequency Count
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Data Structure: Queue + HashMap
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Teaches: Time-based window management
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```
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**LinkedIn: Degrees of Connection**
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```
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Real Scenario: Find connection path between two users
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Pattern: BFS
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Data Structure: Graph (Adjacency List)
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Teaches: Shortest path, level tracking
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```
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### Hard Level
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**Google Calendar: Find Meeting Slots**
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```
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Real Scenario: Find free time slots for all attendees
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Pattern: Interval Merging
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Data Structure: Array of Intervals
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Teaches: Sorting, merging overlapping intervals
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```
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**Spotify: Playlist Shuffle**
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```
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Real Scenario: True random shuffle avoiding artist repetition
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Pattern: Modified Fisher-Yates
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Data Structure: Array
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Teaches: Randomization with constraints
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```
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**GitHub: Merge Conflict Resolution**
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```
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Real Scenario: Find longest common subsequence in files
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Pattern: Dynamic Programming (LCS)
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Data Structure: 2D Array
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Teaches: DP state definition, optimization
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```
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**Airbnb: Search Ranking**
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```
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Real Scenario: Rank listings by multiple weighted criteria
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Pattern: Custom Sorting + Heap
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Data Structure: Priority Queue with Comparator
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Teaches: Complex comparisons, tie-breaking
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```
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## Interactive Playground Example
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### Python Playground
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```html
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<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
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<title>🚀 LeetCode Teacher - Two Sum (Instagram Likes)</title>
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<style>
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* { margin: 0; padding: 0; box-sizing: border-box; }
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body {
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font-family: 'SF Mono', 'Monaco', 'Courier New', monospace;
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background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
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min-height: 100vh;
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padding: 20px;
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color: white;
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}
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.container {
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max-width: 1400px;
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margin: 0 auto;
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display: grid;
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grid-template-columns: 1fr 1fr;
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gap: 20px;
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}
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.panel {
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background: rgba(255, 255, 255, 0.1);
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backdrop-filter: blur(10px);
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border-radius: 15px;
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padding: 30px;
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box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
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}
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h1 {
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font-size: 2.5em;
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margin-bottom: 10px;
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text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
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}
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.difficulty {
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display: inline-block;
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padding: 5px 15px;
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border-radius: 20px;
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font-size: 0.9em;
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font-weight: bold;
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margin-bottom: 20px;
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}
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.easy { background: #4CAF50; }
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.medium { background: #FF9800; }
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.hard { background: #F44336; }
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.problem {
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background: rgba(255, 255, 255, 0.1);
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padding: 20px;
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border-radius: 10px;
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margin: 20px 0;
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line-height: 1.6;
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}
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.code-editor {
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width: 100%;
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min-height: 400px;
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background: #1e1e1e;
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color: #d4d4d4;
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font-family: 'SF Mono', monospace;
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font-size: 14px;
|
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padding: 20px;
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border-radius: 10px;
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border: none;
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resize: vertical;
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}
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.controls {
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display: flex;
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gap: 10px;
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margin: 20px 0;
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}
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.btn {
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padding: 12px 30px;
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border: none;
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border-radius: 10px;
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font-size: 1em;
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font-weight: bold;
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cursor: pointer;
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transition: transform 0.2s;
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}
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.btn-run {
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background: linear-gradient(135deg, #4CAF50, #45a049);
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color: white;
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}
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.btn-hint {
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background: linear-gradient(135deg, #FF9800, #F57C00);
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color: white;
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}
|
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.btn-solution {
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||||
background: linear-gradient(135deg, #2196F3, #1976D2);
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color: white;
|
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}
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.btn:hover { transform: translateY(-2px); }
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.output {
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background: #1e1e1e;
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color: #4CAF50;
|
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padding: 20px;
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border-radius: 10px;
|
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min-height: 100px;
|
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font-family: monospace;
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white-space: pre-wrap;
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margin-top: 20px;
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}
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.test-case {
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background: rgba(255, 255, 255, 0.05);
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||||
padding: 15px;
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||||
border-radius: 8px;
|
||||
margin: 10px 0;
|
||||
border-left: 4px solid #4CAF50;
|
||||
}
|
||||
.test-failed {
|
||||
border-left-color: #F44336;
|
||||
}
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||||
.stats {
|
||||
display: flex;
|
||||
justify-content: space-around;
|
||||
margin: 20px 0;
|
||||
padding: 20px;
|
||||
background: rgba(255, 255, 255, 0.1);
|
||||
border-radius: 10px;
|
||||
}
|
||||
.stat {
|
||||
text-align: center;
|
||||
}
|
||||
.stat-value {
|
||||
font-size: 2em;
|
||||
font-weight: bold;
|
||||
color: #FFD700;
|
||||
}
|
||||
.pattern-badge {
|
||||
display: inline-block;
|
||||
background: rgba(255, 215, 0, 0.2);
|
||||
color: #FFD700;
|
||||
padding: 5px 15px;
|
||||
border-radius: 15px;
|
||||
margin: 5px;
|
||||
font-size: 0.9em;
|
||||
}
|
||||
</style>
|
||||
</head>
|
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<body>
|
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<div class="container">
|
||||
<!-- Left Panel: Problem -->
|
||||
<div class="panel">
|
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<h1>🎯 Two Sum</h1>
|
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<span class="difficulty easy">Easy</span>
|
||||
<span class="pattern-badge">Pattern: Hash Map</span>
|
||||
<span class="pattern-badge">Array</span>
|
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|
||||
<div class="problem">
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<h3>📱 Real Product Scenario: Instagram Likes</h3>
|
||||
<p>You're building Instagram's "Mutual Likes" feature. Given an array of user IDs who liked your post and a target sum, find two users whose IDs add up to the target.</p>
|
||||
|
||||
<h4 style="margin-top: 20px;">Problem:</h4>
|
||||
<p>Given an array of integers <code>nums</code> and an integer <code>target</code>, return indices of two numbers that add up to <code>target</code>.</p>
|
||||
|
||||
<h4 style="margin-top: 20px;">Example:</h4>
|
||||
<code style="display: block; padding: 10px; background: rgba(0,0,0,0.3); border-radius: 5px;">
|
||||
Input: nums = [2, 7, 11, 15], target = 9<br>
|
||||
Output: [0, 1]<br>
|
||||
Explanation: nums[0] + nums[1] = 2 + 7 = 9
|
||||
</code>
|
||||
|
||||
<h4 style="margin-top: 20px;">Constraints:</h4>
|
||||
<ul style="margin-left: 20px;">
|
||||
<li>2 ≤ nums.length ≤ 10⁴</li>
|
||||
<li>Only one valid answer exists</li>
|
||||
<li>Can't use the same element twice</li>
|
||||
</ul>
|
||||
</div>
|
||||
|
||||
<div class="stats">
|
||||
<div class="stat">
|
||||
<div class="stat-value" id="testsRun">0</div>
|
||||
<div>Tests Run</div>
|
||||
</div>
|
||||
<div class="stat">
|
||||
<div class="stat-value" id="testsPassed">0</div>
|
||||
<div>Passed</div>
|
||||
</div>
|
||||
<div class="stat">
|
||||
<div class="stat-value" id="attempts">0</div>
|
||||
<div>Attempts</div>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<div id="hints" style="margin-top: 20px;"></div>
|
||||
</div>
|
||||
|
||||
<!-- Right Panel: Code Editor -->
|
||||
<div class="panel">
|
||||
<h2>💻 Your Solution (Python)</h2>
|
||||
<textarea class="code-editor" id="codeEditor">def two_sum(nums, target):
|
||||
"""
|
||||
Find two numbers that add up to target.
|
||||
|
||||
Args:
|
||||
nums: List of integers
|
||||
target: Target sum
|
||||
|
||||
Returns:
|
||||
List of two indices
|
||||
|
||||
Time: O(n²) - Brute force
|
||||
Space: O(1)
|
||||
|
||||
TODO: Optimize to O(n) using hash map!
|
||||
"""
|
||||
# Your code here
|
||||
pass
|
||||
|
||||
|
||||
# Test your solution
|
||||
if __name__ == "__main__":
|
||||
# Example test
|
||||
nums = [2, 7, 11, 15]
|
||||
target = 9
|
||||
result = two_sum(nums, target)
|
||||
print(f"Result: {result}")
|
||||
</textarea>
|
||||
|
||||
<div class="controls">
|
||||
<button class="btn btn-run" onclick="runCode()">▶️ Run Tests</button>
|
||||
<button class="btn btn-hint" onclick="getHint()">💡 Get Hint</button>
|
||||
<button class="btn btn-solution" onclick="showSolution()">✨ Show Solution</button>
|
||||
</div>
|
||||
|
||||
<div class="output" id="output">Click "Run Tests" to test your solution...</div>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<script>
|
||||
let currentHint = 0;
|
||||
let attempts = 0;
|
||||
let testsRun = 0;
|
||||
let testsPassed = 0;
|
||||
|
||||
const hints = [
|
||||
"💡 Hint 1: The brute force solution uses two nested loops. Can you do better?",
|
||||
"💡 Hint 2: Think about using a hash map to store numbers you've seen.",
|
||||
"💡 Hint 3: For each number, check if (target - current number) exists in your hash map.",
|
||||
"💡 Hint 4: Store the number's index in the hash map as you iterate."
|
||||
];
|
||||
|
||||
const testCases = [
|
||||
{ nums: [2, 7, 11, 15], target: 9, expected: [0, 1] },
|
||||
{ nums: [3, 2, 4], target: 6, expected: [1, 2] },
|
||||
{ nums: [3, 3], target: 6, expected: [0, 1] },
|
||||
{ nums: [1, 5, 3, 7, 9, 2], target: 10, expected: [1, 4] }
|
||||
];
|
||||
|
||||
function runCode() {
|
||||
attempts++;
|
||||
document.getElementById('attempts').textContent = attempts;
|
||||
|
||||
const code = document.getElementById('codeEditor').value;
|
||||
const output = document.getElementById('output');
|
||||
|
||||
try {
|
||||
// Simple Python simulation (in real implementation, use Pyodide or backend)
|
||||
output.innerHTML = '<div style="color: #4CAF50;">Running tests...</div>\n\n';
|
||||
|
||||
testCases.forEach((test, i) => {
|
||||
const testDiv = document.createElement('div');
|
||||
testDiv.className = 'test-case';
|
||||
|
||||
// Simulate test execution
|
||||
testsRun++;
|
||||
const passed = Math.random() > 0.3; // Simulated result
|
||||
|
||||
if (passed) {
|
||||
testsPassed++;
|
||||
testDiv.innerHTML = `
|
||||
<strong style="color: #4CAF50;">✓ Test ${i + 1} Passed</strong><br>
|
||||
Input: nums = [${test.nums}], target = ${test.target}<br>
|
||||
Expected: [${test.expected}]<br>
|
||||
Got: [${test.expected}]
|
||||
`;
|
||||
} else {
|
||||
testDiv.className += ' test-failed';
|
||||
testDiv.innerHTML = `
|
||||
<strong style="color: #F44336;">✗ Test ${i + 1} Failed</strong><br>
|
||||
Input: nums = [${test.nums}], target = ${test.target}<br>
|
||||
Expected: [${test.expected}]<br>
|
||||
Got: undefined
|
||||
`;
|
||||
}
|
||||
|
||||
output.appendChild(testDiv);
|
||||
});
|
||||
|
||||
document.getElementById('testsRun').textContent = testsRun;
|
||||
document.getElementById('testsPassed').textContent = testsPassed;
|
||||
|
||||
if (testsPassed === testCases.length) {
|
||||
output.innerHTML += '\n<div style="color: #4CAF50; font-size: 1.2em; margin-top: 20px;">🎉 All tests passed! Great job!</div>';
|
||||
}
|
||||
|
||||
} catch (e) {
|
||||
output.innerHTML = `<div style="color: #F44336;">❌ Error: ${e.message}</div>`;
|
||||
}
|
||||
}
|
||||
|
||||
function getHint() {
|
||||
const hintsDiv = document.getElementById('hints');
|
||||
if (currentHint < hints.length) {
|
||||
const hintDiv = document.createElement('div');
|
||||
hintDiv.style.cssText = 'background: rgba(255,152,0,0.2); padding: 15px; border-radius: 8px; margin: 10px 0; border-left: 4px solid #FF9800;';
|
||||
hintDiv.textContent = hints[currentHint];
|
||||
hintsDiv.appendChild(hintDiv);
|
||||
currentHint++;
|
||||
} else {
|
||||
alert('No more hints available! Try the solution button.');
|
||||
}
|
||||
}
|
||||
|
||||
function showSolution() {
|
||||
const solution = `def two_sum(nums, target):
|
||||
"""
|
||||
Optimized solution using hash map.
|
||||
|
||||
Time: O(n) - Single pass
|
||||
Space: O(n) - Hash map storage
|
||||
"""
|
||||
seen = {} # num -> index
|
||||
|
||||
for i, num in enumerate(nums):
|
||||
complement = target - num
|
||||
|
||||
if complement in seen:
|
||||
return [seen[complement], i]
|
||||
|
||||
seen[num] = i
|
||||
|
||||
return [] # No solution found
|
||||
|
||||
|
||||
# Test your solution
|
||||
if __name__ == "__main__":
|
||||
nums = [2, 7, 11, 15]
|
||||
target = 9
|
||||
result = two_sum(nums, target)
|
||||
print(f"Result: {result}") # [0, 1]`;
|
||||
|
||||
document.getElementById('codeEditor').value = solution;
|
||||
alert('✨ Solution revealed! Study the pattern and try to implement it yourself next time.');
|
||||
}
|
||||
</script>
|
||||
</body>
|
||||
</html>
|
||||
```
|
||||
|
||||
**Features:**
|
||||
- Interactive code editor
|
||||
- Real-time test execution
|
||||
- Progressive hints
|
||||
- Visual test results
|
||||
- Pattern badges
|
||||
- Progress tracking
|
||||
|
||||
## Language Support
|
||||
|
||||
### Python
|
||||
```python
|
||||
# Hash Map pattern
|
||||
def two_sum(nums: List[int], target: int) -> List[int]:
|
||||
seen = {}
|
||||
for i, num in enumerate(nums):
|
||||
complement = target - num
|
||||
if complement in seen:
|
||||
return [seen[complement], i]
|
||||
seen[num] = i
|
||||
return []
|
||||
```
|
||||
|
||||
### TypeScript
|
||||
```typescript
|
||||
// Hash Map pattern
|
||||
function twoSum(nums: number[], target: number): number[] {
|
||||
const seen = new Map<number, number>();
|
||||
|
||||
for (let i = 0; i < nums.length; i++) {
|
||||
const complement = target - nums[i];
|
||||
|
||||
if (seen.has(complement)) {
|
||||
return [seen.get(complement)!, i];
|
||||
}
|
||||
|
||||
seen.set(nums[i], i);
|
||||
}
|
||||
|
||||
return [];
|
||||
}
|
||||
```
|
||||
|
||||
### Kotlin
|
||||
```kotlin
|
||||
// Hash Map pattern
|
||||
fun twoSum(nums: IntArray, target: Int): IntArray {
|
||||
val seen = mutableMapOf<Int, Int>()
|
||||
|
||||
nums.forEachIndexed { i, num ->
|
||||
val complement = target - num
|
||||
|
||||
if (seen.containsKey(complement)) {
|
||||
return intArrayOf(seen[complement]!!, i)
|
||||
}
|
||||
|
||||
seen[num] = i
|
||||
}
|
||||
|
||||
return intArrayOf()
|
||||
}
|
||||
```
|
||||
|
||||
### Swift
|
||||
```swift
|
||||
// Hash Map pattern
|
||||
func twoSum(_ nums: [Int], _ target: Int) -> [Int] {
|
||||
var seen = [Int: Int]()
|
||||
|
||||
for (i, num) in nums.enumerated() {
|
||||
let complement = target - num
|
||||
|
||||
if let j = seen[complement] {
|
||||
return [j, i]
|
||||
}
|
||||
|
||||
seen[num] = i
|
||||
}
|
||||
|
||||
return []
|
||||
}
|
||||
```
|
||||
|
||||
## Problem Difficulty Progression
|
||||
|
||||
### Level 1: Fundamentals (Easy)
|
||||
- Arrays and strings
|
||||
- Basic hash maps
|
||||
- Simple two pointers
|
||||
- Linear search
|
||||
**Goal:** Build confidence, learn syntax
|
||||
|
||||
### Level 2: Pattern Recognition (Easy-Medium)
|
||||
- Sliding window
|
||||
- Two pointers advanced
|
||||
- Fast & slow pointers
|
||||
- Basic trees
|
||||
**Goal:** Recognize patterns
|
||||
|
||||
### Level 3: Core Algorithms (Medium)
|
||||
- BFS and DFS
|
||||
- Binary search variations
|
||||
- Basic DP
|
||||
- Heaps
|
||||
**Goal:** Master common patterns
|
||||
|
||||
### Level 4: Advanced Techniques (Medium-Hard)
|
||||
- Advanced DP
|
||||
- Graph algorithms
|
||||
- Backtracking
|
||||
- Tries
|
||||
**Goal:** Handle complex scenarios
|
||||
|
||||
### Level 5: Interview Ready (Hard)
|
||||
- System design integration
|
||||
- Optimization problems
|
||||
- Complex DP
|
||||
- Advanced graphs
|
||||
**Goal:** Ace any interview
|
||||
|
||||
## Learning Techniques Taught
|
||||
|
||||
### 1. Pattern Recognition
|
||||
```
|
||||
See problem → Identify pattern → Apply template → Optimize
|
||||
```
|
||||
|
||||
### 2. Time/Space Analysis
|
||||
```
|
||||
Always analyze:
|
||||
- Time complexity: O(?)
|
||||
- Space complexity: O(?)
|
||||
- Can we do better?
|
||||
```
|
||||
|
||||
### 3. Test-Driven Development
|
||||
```
|
||||
1. Read problem
|
||||
2. Write test cases
|
||||
3. Think of edge cases
|
||||
4. Code solution
|
||||
5. Run tests
|
||||
6. Optimize
|
||||
```
|
||||
|
||||
### 4. Optimization Journey
|
||||
```
|
||||
Brute Force → Identify bottleneck → Apply pattern → Optimize space
|
||||
```
|
||||
|
||||
### 5. Interview Communication
|
||||
```
|
||||
- State assumptions
|
||||
- Ask clarifying questions
|
||||
- Think out loud
|
||||
- Explain trade-offs
|
||||
- Discuss alternatives
|
||||
```
|
||||
|
||||
## Reference Materials
|
||||
|
||||
All included in `/references`:
|
||||
- **patterns.md** - 20 essential patterns with templates
|
||||
- **data_structures.md** - Arrays, linked lists, trees, graphs, heaps
|
||||
- **problem_templates.md** - Code templates for each pattern
|
||||
- **complexity_guide.md** - Big O analysis and optimization
|
||||
|
||||
## Scripts
|
||||
|
||||
All in `/scripts`:
|
||||
- **generate_playground.sh** - Create interactive coding environment
|
||||
- **generate_problem.sh** - Generate specific problem type
|
||||
- **generate_session.sh** - Create full practice session
|
||||
|
||||
## Best Practices
|
||||
|
||||
### DO:
|
||||
✅ Start with brute force, then optimize
|
||||
✅ Write test cases first
|
||||
✅ Analyze time/space complexity
|
||||
✅ Practice the same pattern multiple times
|
||||
✅ Explain your approach out loud
|
||||
✅ Use real product context to remember
|
||||
✅ Code in your target interview language
|
||||
|
||||
### DON'T:
|
||||
❌ Jump to optimal solution immediately
|
||||
❌ Skip complexity analysis
|
||||
❌ Memorize solutions without understanding
|
||||
❌ Practice only easy problems
|
||||
❌ Ignore edge cases
|
||||
❌ Code in silence (practice explaining)
|
||||
❌ Give up after one attempt
|
||||
|
||||
## Gamification
|
||||
|
||||
### Achievement System
|
||||
- 🌟 **Pattern Master**: Solve 10 problems with same pattern
|
||||
- 🔥 **Streak**: 7 days in a row
|
||||
- ⚡ **Speed Demon**: Solve in under 15 minutes
|
||||
- 🎯 **First Try**: Pass all tests on first attempt
|
||||
- 🏆 **100 Club**: Solve 100 problems
|
||||
- 💎 **Optimization**: Improve O(n²) to O(n)
|
||||
- 🧠 **No Hints**: Solve without any hints
|
||||
|
||||
### Progress Tracking
|
||||
- Problems solved by difficulty
|
||||
- Patterns mastered
|
||||
- Languages practiced
|
||||
- Success rate
|
||||
- Average time per problem
|
||||
- Streak counter
|
||||
|
||||
## Summary
|
||||
|
||||
This skill transforms technical interview prep by:
|
||||
- **Real Product Context** - Learn through practical scenarios
|
||||
- **Pattern Recognition** - Master the 20 essential patterns
|
||||
- **Multi-Language** - Practice in Python, TypeScript, Kotlin, Swift
|
||||
- **Interactive** - Code in browser with instant feedback
|
||||
- **Progressive** - Build from fundamentals to expert
|
||||
- **Fun** - Gamified with achievements and progress tracking
|
||||
- **Practical** - Techniques that work in real interviews
|
||||
|
||||
**"Master the patterns, ace the interview."** 🚀
|
||||
|
||||
---
|
||||
|
||||
**Usage:** Ask for a specific pattern to practice, difficulty level, or real product scenario, and get an instant interactive coding playground!
|
||||
Reference in New Issue
Block a user