Back to Projects
ActiveLLM Project

Array Playground

Visualize array manipulations, shifts, sliding windows, and two pointer traversals step-by-step with active highlighting.

Target Learning Outcome

Deconstruct how index manipulation, pointer shifts, and sliding windows operate on linear arrays.

Active Lab TerminalRUNNING LIVE
Array Representation
idx 0
12
idx 1
35
idx 2
7
idx 3
19
idx 4
24
idx 5
5
idx 6
8
Value
Index
Preset Patterns Simulations
Execution trace
Array initialized. Choose an action.
01. Problem it solves

Linear Complexity Shifting

Developers often memorize how array operations behave but struggle to visualize why inserting or deleting from arbitrary indexes requires $O(N)$ shifts, or how left and right index bounds move in sliding window algorithms.

This playground provides a visual trace of index values and moving bounds, revealing array mechanisms instantly.

02. Concept it teaches

Pointers and Contiguous Windows

This sandbox teaches critical array concepts:

  • Linear array memory layouts and structures
  • Time complexity of insertions vs. deletions (element shifting)
  • Two Pointers technique for matching sub-sums
  • Sliding Window logic for contiguous range aggregates
  • Pointer boundary conditions verification
03. What I built

Index-highlighting Sandbox Workspace

An interactive array visualizer featuring:

  • Array elements grid displaying values, indices, and active pointer tags.
  • Interactive inputs to Insert (value/index) and Delete elements.
  • Array traversal step-by-step animation highlighting visited cells.
  • Sliding Window window-bounding box animations.
  • Two Pointer inward converging stepping animation.
04. Architecture

Array State Control

Array values state
Index highlight state hooks
Execution logs terminal
05. Tech Stack

Built With

React 19TypeScriptTailwind CSSFramer MotionGitHub
06 & 07. Links

Source & Deploy

GitHub Repository:landing
Live Lab Endpoint:/labs/array-playground
08. Interview Explanation

Defending the Design

Interview Defense Strategy

I implemented the Array Playground to visualize element shifting and pointer-based scans. Seeing pointers move inward in two-pointer mode or windows shift in sliding window mode helps developers build physical intuition for why boundary constraints can be optimized to linear O(N) execution steps.
09. Future Improvements

Roadmap Extensions

  • Integrate dynamic array resizing (Capacity vs. Size limits).
  • Add support for prefix sum visual overlays.
  • Include sorting animations (Bubble, Selection, QuickSort).