Weaving robust data structures with elegant algorithms — one carefully crafted solution at a time.
StructWeave is an algorithm course and coding interview preparation resource featuring data structures and algorithms practice problems. Designed for steady, deliberate improvement, the focus is on solutions that are correct, readable, and educational — the kind that actually stick.
The repository emphasizes understanding over memorization. Master DSA practice through pattern recognition — learn 17 patterns that solve 90% of interview problems. This is a space for building quiet competence rather than flashy brilliance.
- Collection of Practice Problems — Organized by difficulty (20 foundation, 270 easy, 575 medium, 117 hard)
- Foundation Tier — 20 computational thinking problems for building mathematical intuition (Choose to repeat - Math is not hard!)
- 17 Pattern Guides — Master the core patterns that solve 90% of interview problems
- Multiple Solution Approaches — From brute force to optimal, with complexity analysis
- 3-Tier Hint System — Nudge → Direction → Skeleton (learn without spoilers)
- Spaced Repetition Support — Built-in review schedules and practice checklists
- Beginner-Friendly Prerequisites — Big-O notation, debugging strategies, computational thinking
- 5 Detailed Walkthroughs — Step-by-step problem solving demonstrations
- Self-Assessment System — Entry assessment + 4 phase assessments to track progress
- No Platform Lock-in — Pure markdown, works anywhere, forever
- Algorithm patterns that solve 90% of coding interview problems
- Data structure fundamentals — arrays, trees, graphs, heaps, and more
- Problem-solving strategies for technical interviews
- Complexity analysis — Big-O notation, time/space tradeoffs
- Deliberate practice techniques backed by cognitive science research
Complete beginner? → Start with prerequisites/
New to algorithms? → Try problems/foundation/ for computational thinking
Know basics? → Take assessments/entry-assessment.md
Interview prep? → Follow tracks/roadmap.md
Just refreshing? → Jump to strategies/patterns/
- Read Two Pointers Pattern (3 min)
- Open E006 Container With Most Water
- Try solving it — use the collapsible hints if stuck
- Check the complexity analysis table when done
| Problem | Pattern | Why Start Here |
|---|---|---|
| F001 Multiples of 3 or 5 | Math | Modulo, loops, inclusion-exclusion |
| E001 Two Sum | Hash Map | Classic, teaches complement search |
| E014 Valid Parentheses | Stack | Fundamental data structure |
| M002 Longest Substring | Sliding Window | Core interview pattern |
These patterns solve the vast majority of algorithm problems:
| Pattern | When to Use | Guide |
|---|---|---|
| Two Pointers | Sorted arrays, pair finding | two-pointers.md |
| Sliding Window | Contiguous subarrays/substrings | sliding-window.md |
| Binary Search | Sorted data, monotonic functions | binary-search.md |
| Prefix Sum | Range sum queries | prefix-sum.md |
| Monotonic Stack | Next greater/smaller element | monotonic-stack.md |
| Cyclic Sort | Numbers 1-n, missing/duplicate | cyclic-sort.md |
| Merge Intervals | Overlapping ranges | merge-intervals.md |
| Two Heaps | Median, balanced partitions | two-heaps.md |
| K-way Merge | Merge K sorted sequences | k-way-merge.md |
| Top K Elements | Kth largest/smallest | heaps.md |
| Graph BFS/DFS | Traversal, shortest path | graph-traversal.md |
| Topological Sort | Dependencies, ordering | topological-sort.md |
| Backtracking | All combinations/permutations | backtracking.md |
| Dynamic Programming | Optimal substructure | dynamic-programming.md |
| Greedy | Local optimal → global optimal | greedy.md |
| Divide & Conquer | Split, solve, combine | divide-and-conquer.md |
| Bitwise XOR | Find unique elements | bitwise-xor.md |
See the Pattern Decision Guide for a flowchart on choosing the right pattern.
| Track | Duration | For Who | Start Here |
|---|---|---|---|
| Beginner | 10-12 weeks | Complete beginners, bootcamp grads | Prerequisites |
| Foundation | 2-3 weeks | Build computational thinking first | Foundation Problems |
| Interview Prep | 8-10 weeks | Experienced devs preparing for interviews | Entry Assessment |
| Refresher | 4 weeks | Rusty engineers getting back in shape | Pattern Guides |
| Maintenance | 3-5 hrs/week | Staying sharp long-term | Mixed Practice |
See tracks/roadmap.md for the complete 4-phase learning path.
-
First Principles Thinking Understand why patterns work, not just how. Every pattern guide explains the fundamental constraint it addresses.
-
Pattern-First Learning Pattern recognition beats problem memorization. Learn 17 patterns well, and you can solve hundreds of problems.
-
Science-Backed Practice Spaced repetition, active recall, deliberate practice. Each problem includes review checklists based on cognitive research.
- Clarity over cleverness — One-liners that no one understands help no one
- Understanding over speed — Quiet competence beats flashy tricks
- "Good enough" first — Correct and readable before optimized
- Progress over perfection — Steady improvement, one problem at a time
"Be so good they can't ignore you." — Steve Martin
Research consistently shows that deliberate practice, not innate talent, separates world-class performers from everyone else. What looks like natural ability is usually the result of years of focused, intentional effort.
| Book | Core Insight |
|---|---|
| Peak (Ericsson & Pool) | Deliberate practice builds mental representations that enable expertise |
| Talent Is Overrated (Colvin) | Excellence comes from continually identifying and improving weak points |
| Grit (Duckworth) | Passion + perseverance beats talent every time |
| So Good They Can't Ignore You (Newport) | Career capital comes from stretching beyond your current abilities |
It's not mindless repetition. It's structured, uncomfortable growth:
- Work at the edge of ability — Comfort zone → Learning zone → Panic zone. Growth happens in the learning zone.
- Get immediate feedback — Know whether your approach works before moving on
- Focus on weaknesses — Not just what you're already good at
- Repeat with intention — Each attempt should be a conscious effort to improve
"If you're not uncomfortable, you're probably stuck at an 'acceptable level.'" — Cal Newport
Your brain physically changes through practice. Neuroscience research shows mathematical practice increases grey matter density in regions critical for reasoning. This isn't metaphor—it's measurable brain architecture.
30 minutes daily beats 4 hours weekly. Consistency builds neural pathways. Sporadic cramming doesn't.
Angela Duckworth's research identifies what sustains long-term practice:
- Interest — You can't persevere at something you don't care about
- Practice — Deliberate, focused improvement (not just showing up)
- Purpose — Connecting your work to something larger than yourself
- Hope — Believing you can improve, even when progress feels slow
The problems you struggle with are the most valuable. Don't skip them—schedule them for more reviews. Like kintsugi (金継ぎ), where broken pottery is repaired with gold, your struggles become your strength.
See the Practice Guide for structured approaches to deliberate practice.
Contributions are welcome! See CONTRIBUTING.md for guidelines.
Ways to help:
- Improve problem explanations for clarity
- Add alternative solution approaches
- Fix typos and broken links
- Find logical errors in problems description
- Enhance pattern guides with examples
- Add practice drills
Important: All content must be original or properly paraphrased. No direct copying from any platform.
MIT License — Use freely.
This repository synthesizes wisdom from:
- Classic algorithm textbooks (CLRS, Skiena)
- Research on deliberate practice and spaced repetition
- The open-source algorithm education community
- Algorithmic problems and discussions found across the internet
This is a free, open-source educational resource. The problems here are inspired by common algorithmic challenges discussed in textbooks, forums, and online communities over decades. The intent is purely educational — to provide a structured framework for learning, nothing more.
If you find this useful, pay it forward. Teach someone else.
StructWeave — Interlacing data structures with algorithmic insight.
Practice problems · Clean implementations · Progressive difficulty
One carefully woven solution at a time.