Structure Solver - Project Plan & Documentation

📋 Table of Contents

• Project Overview
• Core Features
• Development Phases
• Database Schema
• User Flows
• Tech Stack
• Getting Started

🚀 Project Overview

Structure Solver is a comprehensive, MERN-stack-based web platform designed to be a one-stop solution for learning, practicing, and mastering Data Structures and Algorithms (DSA). It combines educational content, a full-featured online IDE, personalized user dashboards, and community engagement features to guide users from beginner to interview-ready.

Tech Stack

• Frontend: React (with JSX), TailwindCSS
• Backend: Node.js, Express.js
• Database: MongoDB
• Code Execution: Secure third-party API (e.g., Judge0)

🎯 Core Features

A. Learning & Content

• DSA Topic Pages: Detailed articles with explanations, pseudo-code, and practice problems
• DSA Practice Sheets: Curated problem lists (e.g., "SDE Sheet," "Blind 75")
• Learning Roadmaps: Guided paths for different goals
• Company-Specific Tracks: Practice sheets targeting top tech companies
• Embedded Video Explanations: Video content on problem pages
• Interactive Visualizers: JavaScript-based algorithm animations

B. The Online IDE & Practice

• In-Built Code Editor: Multi-language support (C++, Java, Python, JavaScript)
• Secure Code Execution: Sandboxed environment via third-party API
• Custom Test Cases: User-defined test cases for debugging
• Submission & Judging: Automated test case evaluation
• Submission History: Track all past attempts and results

C. User Dashboard & Gamification

• User Authentication: Secure registration and login
• Personalized Dashboard: Key stats and progress tracking
• Daily Streak System: Consecutive day counter with visual calendar
• Ranking & Leaderboard: Global ranking based on performance
• Progress Visualization: GitHub-style heatmap or skill tree
• DSA Tests: Timed problem-solving assessments
• Hints System: Point-based hint unlocking

D. Community & Social

• Discussion Boards: Problem-specific forums
• Solution Sharing: User-submitted solutions with voting
• Public Profiles: Shareable user statistics and achievements
• Mock Interviews: Shared IDE with video/audio chat via WebRTC

🗓️ Development Phases

Phase 1: The Core Content & Foundation (MVP)

Goal: Build a non-interactive "knowledge base" and establish core architecture

• User Authentication (Login/Signup)
• Database Schemas: User, Problem, Topic, Sheet
• Admin Interface for content management
• Basic Topic, Sheet, and Problem pages
• Manual progress tracking ("Mark as Complete")

Phase 2: The Interactive IDE

Goal: Enable interactive problem solving

• Code editor integration (Monaco/CodeMirror)
• Code execution API integration (Judge0)
• Custom test case execution
• Automated submission judging
• Submission history tracking

Phase 3: Gamification & Engagement

Goal: Build user retention features

• Daily streak system implementation
• Ranking and leaderboard system
• Progress visualization (heatmaps)
• DSA test/assignment feature
• Hints system with points

Phase 4: Community & Advanced Features

Goal: Create collaborative ecosystem

• Per-problem discussion boards
• Solution sharing with voting
• Public user profiles
• Mock interview feature (shared editor + WebRTC)
• Interactive algorithm visualizers

🗄️ Database Schema

classDiagram
    class User {
        +String userId
        +String username
        +String email
        +String passwordHash
        +Int streak
        +Int points
        +Date lastActive
        +String[] solvedProblemIds
        +String[] attemptedProblemIds
        +Object progressHeatmap
    }

    class Problem {
        +String problemId
        +String title
        +String description
        +String difficulty
        +String[] tags
        +String topicId
        +Object starterCode
        +Object hiddenTestCases
    }

    class Topic {
        +String topicId
        +String name
        +String description
        +String[] problemIds
    }

    class Sheet {
        +String sheetId
        +String name
        +String description
        +String[] problemIds
    }

    class Submission {
        +String submissionId
        +String userId
        +String problemId
        +String code
        +String language
        +String status
        +String output
        +Date timestamp
    }

    class DiscussionPost {
        +String postId
        +String userId
        +String problemId
        +String content
        +Date timestamp
        +String parentPostId
    }

    class Solution {
        +String solutionId
        +String userId
        +String problemId
        +String title
        +String explanation
        +String code
        +String language
        +Int upvotes
    }

    User "1" -- "0..*" Submission
    User "1" -- "0..*" DiscussionPost
    User "1" -- "0..*" Solution
    Problem "1" -- "0..*" Submission
    Problem "1" -- "0..*" DiscussionPost
    Problem "1" -- "0..*" Solution
    Topic "1" -- "0..*" Problem
    Sheet "1" -- "0..*" Problem

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🔄 User Flows

User Registration & Login

flowchart TD
    A[Start] --> B{User visits site};
    B --> C[Clicks Login/Register];
    C --> D{Has account?};
    D -- No --> E[Shows Register Form];
    E --> F[User submits info];
    F --> G{Info valid?};
    G -- No --> E;
    G -- Yes --> H[Create User in DB];
    H --> I[Generate auth token];
    I --> K[Redirect to Dashboard];
    D -- Yes --> J[Shows Login Form];
    J --> L[User submits credentials];
    L --> M{Credentials valid?};
    M -- No --> J;
    M -- Yes --> I;
    K --> Z[End];

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Problem Solving Workflow

flowchart TD
    A[User selects a Problem] --> B[View Problem Page];
    B --> C[Writes code in IDE];
    C --> D{Action?};
    D -- Run --> E[User writes Custom Test Cases];
    E --> F[Send Code, Test Cases to API];
    F --> G[API executes code];
    G --> H[Return output stdout/stderr];
    H --> C;
    D -- Submit --> I[Send Code, Language, ProblemID to API];
    I --> J[API executes code against Hidden Test Cases];
    J --> K{All tests pass?};
    K -- No --> L[Return Wrong Answer, TLE, etc.];
    L --> M[Save Submission to DB];
    M --> C;
    K -- Yes --> N[Return Accepted];
    N --> O[Save Submission to DB];
    O --> P[Update User's solved list, points, streak];
    P --> Q[Unlock Discussion & Solutions tabs];
    Q --> B;

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Mock Interview Flow

flowchart TD
    A[User A navigates to Mock Interview page] --> B[Clicks "Create Session"];
    B --> C[Generate unique session link];
    C --> D[User A shares link with User B];
    D --> E[User B joins link];
    E --> F[Both users connected via WebRTC];
    F --> G[Shared IDE is loaded];
    G --> H[User A Interviewer picks a problem];
    H --> I[User B Interviewee codes solution];
    I --> J{Session ends};
    J --> K[Both users disconnect];

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🛠️ Getting Started

Prerequisites

• Node.js (v14 or higher)
• MongoDB
• npm or yarn

Installation

# Clone the repository
git clone https://github.com/your-username/structure-solver.git

# Install backend dependencies
cd backend
npm install

# Install frontend dependencies
cd ../frontend
npm install

Environment Setup

Create .env files in both backend and frontend directories with appropriate configuration variables.

Development

# Start backend server
cd backend
npm run dev

# Start frontend development server
cd frontend
npm start

📞 Contact & Support

For questions, suggestions, or contributions, please contact the development team or create an issue in the repository.

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