Leetcode C++ IntelliSense

A lightweight Chrome Extension (Manifest V3) that provides VS Code-style autocomplete and IntelliSense for C++ inside LeetCode's Monaco code editor.

All parsing and completion logic runs entirely locally in your browser with zero latency and no external network dependencies.

---

Features

1. Scope-Aware Variable Autocomplete

• Automatically discovers local variables, loop identifiers, and method parameters.
• Filters out variables outside the current block scope.

2. Type-Aware Container Autocomplete

Typing . or -> on a variable displays only the methods relevant to that specific C++ container:

• vector: push_back, emplace_back, pop_back, size, empty, clear, front, back, begin, end, insert, erase, resize, reserve, assign
• string: length, size, substr, find, rfind, push_back, pop_back, empty, clear, front, back, append, compare, c_str
• unordered_map / map: insert, emplace, erase, find, count, contains, size, empty, clear, at, reserve
• set / unordered_set: insert, emplace, erase, find, count, contains, size, empty, clear, lower_bound, upper_bound
• stack / queue / priority_queue: push, pop, top / front, back, size, empty
• deque: push_back, push_front, pop_back, pop_front, front, back, size, empty, clear
• pair: first, second
• ListNode / TreeNode / Node: val, next, left, right, neighbors, random

3. Typo Tolerance & Spelling Matching

• Resolves minor spelling typos on variable names (e.g., vnums. resolves to nums. and displays vector operations).
• Filters methods dynamically as you type characters after the member access trigger (e.g., nums.pu filters to push_back and pop_back).

4. C++ Keywords, Constants & Standard Algorithms

• Primitive types: int, long long, double, float, char, bool, void, auto, size_t
• Constants: INT_MAX, INT_MIN, LLONG_MAX, LLONG_MIN, nullptr, true, false
• STL algorithms: sort, reverse, max, min, abs, accumulate, count, swap, lower_bound, upper_bound, binary_search, to_string, stoi, stoll, make_pair, sqrt, pow, gcd, lcm

5. Competitive Programming Snippets

• fori -> for (int i = 0; i < n; ++i)
• fore -> for (auto& x : container)
• sortv -> sort(v.begin(), v.end())
• all / rall -> v.begin(), v.end() / v.rbegin(), v.rend()
• bfs / dfs / binsearch -> Standard algorithmic templates
• fastio -> ios_base::sync_with_stdio(false); cin.tie(NULL);

---

Installation

1. Build the Extension

Ensure you have Node.js installed, then run:

npm install
npm run build

The compiled extension bundle will be generated in the dist/ directory.

2. Load into Chrome

1. Open Google Chrome and navigate to chrome://extensions.
2. Enable Developer mode using the toggle in the top-right corner.
3. Click Load unpacked in the top-left toolbar.
4. Select the dist/ folder from this repository.

3. Usage

1. Open any problem on LeetCode.
2. Select C++ as the active language in the code editor.
3. Start typing to view suggestions.

---

Project Structure

.
├── manifest.json            # Chrome Manifest V3 configuration
├── package.json             # Build scripts and dependencies
├── tsconfig.json            # TypeScript compiler configuration
├── build.js                 # Esbuild build script
├── src/
│   ├── content/
│   │   └── content.ts       # Extension content script
│   ├── inject/
│   │   └── main.ts          # Main-world script interacting with Monaco Editor
│   ├── engine/
│   │   ├── cppParser.ts     # C++ tokenizer, scope tracker & fuzzy matcher
│   │   ├── stlDefinitions.ts# C++ STL signatures and documentation
│   │   ├── snippets.ts      # Competitive programming snippets
│   │   └── completionProvider.ts # Monaco CompletionItemProvider adapter
│   └── popup/
│       ├── popup.html       # Extension settings UI
│       ├── popup.css        # Clean developer settings styling
│       └── popup.ts         # Settings sync logic
└── dist/                    # Compiled extension ready for Chrome

---

Contributing

Contributions are welcome! If you face any issues, bugs, or have suggestions, please feel free to contribute by raising an issue on GitHub.

---

License

MIT