★ PTR — Dereference the World

A 2D puzzle-platformer where you ARE the memory pointer. Navigate living data structures. Don't segfault.

🎮 Play Now: ptr-game.vercel.app 📦 Source: github.com/tejasdas/starptr 🏆 Built for: Vihaan 9 × GoAlgo "Game Up Your DSA" Hackathon — April 2026

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Gameplay

📹 60-second demo: demo.gif — record with ! ./record_demo.sh then drop here

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What is ★ PTR?

*PTR teaches Data Structures through physical constraint, not explanation. Each level IS a data structure. The game world's physics enforce its algorithmic rules. There is no popup. There is no tutorial. The constraint is the gameplay.

Zone	Data Structure	Core Constraint
🟩 Array Plains	Array	O(1) teleport access. Race O(log n) binary search vs O(n) enemy.
🟦 Stack Dungeon	Stack (LIFO)	Only stand on the top block. Survive 30 s of auto-pushes by popping.
🌿 Linked List Jungle	Singly Linked List	No random access — follow next vines only. Detect cycles. Repair severed pointers before the list dissolves.

The DSA rules aren't popups. They are the laws of physics.

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DSA Concepts Covered

Zone	Concept	Complexity Demonstrated
Array Plains	Arrays · Binary Search · Linear Search	O(1) access · O(log n) search · O(n) enemy scan
Stack Dungeon	Stack LIFO · Push · Pop · Overflow	O(1) push/pop
Linked List Jungle	Traversal · Insert · Delete · Floyd's Cycle Detection	O(n) traversal · O(1) insert/delete at pointer · O(n) / O(1) cycle detection

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Controls

Input	Action
← → / A D	Move *ptr
↑ / W	Jump
Click box or SPACE	Binary search step (Zone 1)
SPACE / S / ↓	Pop stack block (Zone 2)
→	Traverse ptr = ptr->next (Zone 3)
R	Repair severed vine (Zone 3 corruption phase)
SPACE	Cut detected cycle (Zone 3 Floyd's phase)
ESC	Pause / open DSA Codex

Touch devices: on-screen D-pad (↑ ← →) + A (action) + R (repair) appear automatically.

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HUD System

• Operation Log — live terminal log of every DSA operation (ptr = ptr->next, push(42), etc.)
• Complexity Meter — color-coded badge: 🟢 O(1) / O(log n) · 🟡 O(n) · 🔴 O(n²)
• Memory Map — mini-map of the current data structure topology with player position
• DSA Codex — unlocks after each zone; shows pseudocode + Big-O table as a study reference

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How to Run Locally

git clone https://github.com/tejasdas/starptr
cd starptr
npm install
npm run dev
# Open http://localhost:5173

Requirements: Node 18+, npm 9+

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Tech Stack

Layer	Technology
Game Engine	Phaser.js 3 — Canvas rendering, Arcade physics
UI / HUD	React 18 — overlay layer for HUD, menus, Codex
State	Zustand — game state, pause, codex entries
Styling	Tailwind CSS v4 — React overlay only
Build	Vite — HMR dev server
Language	TypeScript — strict mode throughout
Audio	Web Audio API — procedural 8-bit synthesis, no external files
Hosting	Vercel — instant GitHub CI/CD

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Architecture

React Shell (App.tsx)
├── HUD (ComplexityMeter · MemoryMap · OperationLog)
├── TouchControls  ← virtual D-pad, touch-only
├── PauseMenu + DSA Codex
└── PhaserGame (Canvas)
         ↕ OperationBus (mitt event emitter)
    Phaser Scenes
    ├── BootScene → MainMenuScene
    ├── Zone1_Array   (binary search race)
    ├── Zone2_Stack   (survival mode)
    └── Zone3_LinkedList (traversal · Floyd's · corruption)

Key decision: DSA constraints are Phaser physics, not UI guards. In the Linked List zone there are literally no platforms between nodes. The engine enforces the data structure.

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Design Philosophy

"You don't learn that linked list search is O(n). You LIVE it — you traverse every vine because the world has no other path."

The Operation Log is passive and always visible. Judges see every DSA operation in real-time without the game pausing to explain it. The Codex fills in after each zone as an optional reference, never interrupting play.

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Project Structure

src/
├── scenes/
│   ├── MainMenuScene.ts      # glitch intro + typewriter boot sequence
│   ├── Zone1_Array.ts        # binary search race
│   ├── Zone2_Stack.ts        # LIFO survival
│   └── Zone3_LinkedList.ts   # traversal + Floyd's + corruption enemy
├── entities/
│   └── Player.ts             # *ptr character, keyboard + touch input
├── components/
│   ├── HUD.tsx               # ComplexityMeter · MemoryMap · OperationLog
│   ├── PauseMenu.tsx         # pause overlay + DSA Codex tabs
│   └── TouchControls.tsx     # on-screen D-pad (touch devices only)
├── store/
│   ├── gameStore.ts          # Zustand state
│   └── codexEntries.ts       # pseudocode + Big-O for all zones
├── audio/
│   └── soundManager.ts       # Web Audio API 8-bit SFX
├── input/
│   └── virtualInput.ts       # shared touch ↔ Phaser input bridge
└── OperationBus.ts           # mitt event bus (game → HUD)

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Built for Vihaan 9 × GoAlgo "Game Up Your DSA" hackathon. Solo project by Tejas Das, DTU CSE — April 2026.

"You are the pointer. Navigate or segfault."