This repo is intended for any individual wanting to improve their problem solving skills for software engineering interviews.
Problems are grouped under their respective subtopic, in order to focus on repeatedly applying common patterns rather than randomly tackling questions.
All questions are available on leetcode.com with some requiring leetcode premium.
To find the greatest amount of success when practicing, it is highly recommended to know the methods and runtimes of the following data structures and their operations:
- Arrays
- Maps
- Linked Lists
- Queues
- Heaps
- Stacks
- Trees
- Graphs
In addition, you should have a good grasp on common algorithms such as:
- Breadth-first search
- Depth-first search
- Binary search
- Recursion
This pdf contains information for the main data structures in Java.
Other useful methods to know include substring(), toCharArray(), Math.max(),
Math.min(), and Arrays.fill().
The entire question list can be found here: https://seanprashad.com/leetcode-patterns/.
Each problem now includes optimal time and space complexity information. This helps you:
- Understand the efficiency of solutions
- Prioritize problems based on complexity
- Prepare for interview discussions about optimization
The complexity values are displayed in the main question table and reflect the optimal pattern-based solution for each problem.
Comprehensive guides for each coding pattern are now available in the /guides directory. Each guide includes:
- Core Concept: Clear explanation of what the pattern is and why it exists
- When to Use: Key problem characteristics that signal this pattern is applicable
- Template Code: Generalized code templates in Python and JavaScript showing the structure
- Related Problems: Links back to relevant problems in the main list
- Time & Space Complexity: Complexity analysis for the pattern
- Tips & Best Practices: Practical advice for applying the pattern
Access the guides:
- Through the Pattern Guides tab in the web interface
- Directly in the repository:
/guides - Pattern badges in the question table are clickable and link to their respective guides
Available patterns:
- Arrays, BFS, Backtracking, Binary Search, Bit Manipulation, Bucket Sort
- DFS, Design, Dynamic Programming, Fast & Slow Pointers
- Graph, Greedy, Heap, In-place reversal of a linked list
- Intervals, QuickSelect, Sliding Window, Sorting
- Topological Sort, Trie, Two Pointers, Union Find
Solutions written in Java can be found in the solutions branch.
Think a question should/shouldn't be included? Wish there was another feature? Feel free to open an issue with your suggestion!
This list is heavily inspired from Grokking the Coding Interview with additional problems extracted from the Blind 75 list and this hackernoon article on 14 patterns to ace any coding interview question.