Faster-OJ.nvim

⚡ Build a complete Competitive Programming automation workflow in Neovim.

Faster-OJ.nvim is a Neovim plugin designed for Competitive Programming. It integrates problem fetching, local judging, stress testing, and automated submission into a distraction-free workflow.

✨ Core Features

Fully Automated Workflow: Fetch problems via Competitive Companion and submit with the Faster-OJ browser extension.
Local Judge: Concurrent test execution with time/memory measurement. Lexical fuzzy matching (obscure) and memory offset compensation.
Stress Testing (对拍): Run two solutions against the same inputs — catch edge cases fast.
Dual-Style UI: Float (floating windows) and Split (native Neovim splits) modes. Switch on the fly with f.
Smart Finder: Integrates with snacks.nvim, telescope.nvim, fzf-lua, mini.pick, or vim.ui.select.
Robust Quoting: Stress test arguments support three quoting styles — "...", '...', and C++ raw strings R"(...)" — for paths with spaces and special characters.

🚀 Recommended Workflow

Start services — :FOJ launches HTTP + WebSocket servers
Fetch a problem — Click a problem link in your browser; the Competitive Companion extension sends it to Neovim. A source file and test data are created automatically in work_dir
Write your solution — Edit the generated file
Judge locally — <leader>cdt compiles and runs all test cases. Results open in a multi-panel UI with side-by-side diff
Stress test (optional) — <leader>cdP picks two solutions interactively, or specify paths: :FOJ stress correct=path:"brute.cpp" test=path:"solve.cpp"
Submit — <leader>cdr sends the solution via WebSocket through the browser extension

📦 Installation

Dependencies

Neovim >= 0.9
Browser Extensions:
- Competitive Companion — receives problems
- Faster-OJ Browser Extension — submits solutions
Language toolchains as needed (gcc/g++, python3, node, etc.)

Minimal Configuration (lazy.nvim)

{
  "xiaocrq/faster-oj.nvim",
  opts = {},
}

Recommended Configuration

Only non-default overrides shown.

local code_path = vim.fn.expand("~/Work/Program/CodeForces")

{
  "xiaocrq/faster-oj.nvim",
  opts = {
    warning_msg = true,
    work_dir = code_path,
    temp_dir = code_path .. "/.temp",
    data_dir = code_path .. "/.problem",
    solve_dir = code_path .. "/.solve",
    template_dir = code_path .. "/.template",
    template_default = code_path .. "/.template/template.cpp",
  },
}

To customize compile/run commands, override compile_command / run_command .

⌨️ Recommended Keymaps

local map = vim.keymap.set
local opts = { noremap = true, silent = true }

-- Service
map("n", "<leader>cda", ":FOJ<CR>",              vim.tbl_extend("force", opts, { desc = "FOJ: Start services" }))
map("n", "<leader>cdq", ":FOJ stop<CR>",         vim.tbl_extend("force", opts, { desc = "FOJ: Stop services" }))
map("n", "<leader>cdr", ":FOJ submit<CR>",       vim.tbl_extend("force", opts, { desc = "FOJ: Submit solution" }))

-- Judge & UI
map("n", "<leader>cdt", ":FOJ run<CR>",          vim.tbl_extend("force", opts, { desc = "FOJ: Compile and judge" }))
map("n", "<leader>cdT", ":FOJ test<CR>",         vim.tbl_extend("force", opts, { desc = "FOJ: Judge only (skip compile)" }))
map("n", "<leader>cdu", ":FOJ show<CR>",         vim.tbl_extend("force", opts, { desc = "FOJ: Reopen last session" }))
map("n", "<leader>cdU", ":FOJ show test split<CR>", vim.tbl_extend("force", opts, { desc = "FOJ: Show tests (split)" }))
map("n", "<leader>cde", ":FOJ show edit<CR>",    vim.tbl_extend("force", opts, { desc = "FOJ: Toggle test editor" }))
map("n", "<leader>cdC", ":FOJ close<CR>",         vim.tbl_extend("force", opts, { desc = "FOJ: Close all UI windows" }))

-- Data management
map("n", "<leader>cds", ":FOJ solve<CR>",        vim.tbl_extend("force", opts, { desc = "FOJ: Mark as solved" }))
map("n", "<leader>cdS", ":FOJ solve back<CR>",   vim.tbl_extend("force", opts, { desc = "FOJ: Undo solved mark" }))
map("n", "<leader>cdd", ":FOJ erase<CR>",        vim.tbl_extend("force", opts, { desc = "FOJ: Delete problem data" }))

-- Finder
map("n", "<leader>cdc", ":FOJ find template<CR>", vim.tbl_extend("force", opts, { desc = "FOJ: Find templates" }))
map("n", "<leader>cdp", ":FOJ find problem<CR>",  vim.tbl_extend("force", opts, { desc = "FOJ: Find problem files" }))
map("n", "<leader>cdj", ":FOJ find data<CR>",     vim.tbl_extend("force", opts, { desc = "FOJ: Find problem data" }))

-- Stress testing
map("n", "<leader>cdP", ":FOJ stress correct=find: test=find:<CR>",
    vim.tbl_extend("force", opts, { desc = "FOJ: Stress test" }))

🛠 Commands

Service

Command	Description
`:FOJ`	Start HTTP + WebSocket services (switches to `work_dir` first)
`:FOJ start [mod]`	Start mode: `all` / `http` / `ws`
`:FOJ stop [mod]`	Stop services

Judge & UI

Command	Description
`:FOJ run`	Save, compile, and run all test cases
`:FOJ test`	Run test cases without recompiling
`:FOJ show [sub1] [sub2]`	Reopen last session or toggle specified UI (see below)
`:FOJ close [sub]`	Close UI windows (no arg = close all)
`:FOJ edit`	Toggle test case editor (alias for `:FOJ show edit`)

show arguments:

`sub1`	`sub2` (optional)	Action
(none)	—	Reopen last active session; no-op if no history
`test`	—	Toggle test viewer (default style)
`test`	`float` / `split`	Test viewer with specific style
`edit`	—	Toggle test case editor (default style)
`edit`	`float` / `split`	Editor with specific style
`stress`	—	Toggle stress viewer (if prior results exist)
`stress`	`float` / `split`	Stress viewer with specific style

close arguments: test / edit / stress (no arg = close all).

Dual-style behavior: Press f inside any UI window to toggle between float and split. Different viewers (test, edit, stress) can coexist as long as they use different styles — e.g., TestUI in float + EditUI in split. Switching a viewer's style automatically closes any other viewer using the target style, ensuring at most one float and one split window globally.

Submit

Command	Description
`:FOJ submit`	Send code to browser extension via WebSocket

Problem Management

Command	Description
`:FOJ solve`	Move problem to `solve_dir`, record history. Detects duplicates and handles via `confirm_on_duplicate`
`:FOJ solve back`	Undo last solve (one entry at a time, LIFO stack order)
`:FOJ erase`	Delete problem source + data directory

Finder

Command	Description
`:FOJ find template`	Browse templates in `template_dir`
`:FOJ find problem`	Browse source files in `work_dir`
`:FOJ find data`	Browse problem data in `data_dir`

Stress Testing

Command	Description
`:FOJ stress`	Re-run last stress test
`:FOJ stress correct=type:val test=type:val [data=type:val] [time=N] [mem=N]`	Run stress test

Parameters:

Parameter	Type	Description
`correct`	`path:FILE` or `find:DIR`	Reference solution
`test`	`path:FILE` or `find:DIR`	Solution under test
`data`	`path:P1\nP2` / `find:DIR` / `data:RAW`	Input data (optional: auto-loads from correct/test problem dir)
`time`	integer (ms)	Time limit per case (default: `default_time_limit`)
`mem`	integer (MB)	Memory limit per case (default: `default_memory_limit`)

Values support three quoting styles for paths containing spaces or special characters:

Double quotes: "..." — single quotes: '...' — C++ raw string: R"(...)" / R"delim(...)delim"

Examples:

" Pick both files interactively (data auto-loaded from problem dirs)
:FOJ stress correct=find: test=find:

" Direct paths
:FOJ stress correct=path:brute.py test=path:solve.cpp

" Paths with spaces (quoted)
:FOJ stress correct=path:"my brute.cpp" test=path:'solve.cpp'

" C++ raw string quoting
:FOJ stress correct=path:R"(brute.cpp)" test=path:R"(solve.cpp)"

" With raw data and time/memory limits
:FOJ stress correct=path:a.cpp test=path:b.cpp data=data:5\n1 2 3 time=1000 mem=512

⚙️ Configuration Reference

Paths

Parameter	Type	Default	Description
`work_dir`	string	`vim.fn.stdpath("data") .. "/faster-oj"`	Base working directory
`data_dir`	string	`".problem"`	Problem data directory (relative to `work_dir`)
`solve_dir`	string	`".solve"`	Solved problems archive (relative to `work_dir`)
`temp_dir`	string	`".temp"`	Temporary files (relative to `work_dir`)
`template_dir`	string	`""`	Template directory
`template_default`	string	`""`	Default template file
`template_default_ext`	string	`".cpp"`	Fallback language extension
`auto_open`	boolean	`true`	Auto-open file on problem receipt

Server

Parameter	Type	Default	Description
`http_host`	string	`"127.0.0.1"`	HTTP bind address
`http_port`	integer	`10043`	HTTP port
`ws_host`	string	`"127.0.0.1"`	WebSocket bind address
`ws_port`	integer	`10044`	WebSocket port
`server_mod`	string	`"all"`	Startup mode: `http` / `ws` / `all`
`max_time_out`	integer	`5`	Browser connection timeout (s)

Judge

Parameter	Type	Default	Description
`max_workers`	integer	`5`	Max concurrent workers
`obscure`	boolean	`true`	Lexical fuzzy matching
`warning_msg`	boolean	`false`	Show compile warnings in results
`clipboard_submit`	boolean	`false`	Copy code to clipboard on submit
`default_time_limit`	integer	`2000`	Fallback time limit (ms)
`default_memory_limit`	integer	`256`	Fallback memory limit (MB)
`linux_mem_offset`	integer	`-2900`	Linux memory offset (KB)
`macos_mem_offset`	integer	`-1500`	macOS memory offset (KB)
`max_solve_history`	integer	`100`	Max solve history entries
`confirm_on_duplicate`	boolean	`false`	Confirm before overwriting duplicate problem in `solve_dir`
`debug`	boolean	`false`	Debug logging

Variable Expansion

Commands support $(VAR) / @VAR / %VAR%:

Variable	Expands to
`$(FNAME)`	Full filename (`123A.cpp`)
`$(FNOEXT)`	Filename without extension (`123A`)
`$(FABSPATH)`	Absolute path to source file
`$(DIR)`	Directory of source file

Compile & Run Commands

Tables keyed by file extension. Each entry: exec + optional args.

compile_command = {
  cpp = {
    exec = "g++",
    args = { "-std=c++20", "-O2", "$(FABSPATH)", "-o", "$(DIR)/$(FNOEXT)" },
  },
},
run_command = {
  cpp = { exec = "$(DIR)/$(FNOEXT)" },
},

UI Layouts

Each UI (tc_ui, tc_edit_ui, stress_ui) supports two styles: float (floating windows) and split (native Neovim splits). Press f inside any UI window to toggle between them.

tc_ui = {
  default_style = "float",            -- "float" | "split"
  mappings = {                        -- shared across styles
    close = { "<esc>", "<C-c>", "q", "Q" },
    toggle_style = { "f" },           -- NEW: switch float/split
    -- ... view, focus_next, etc.
  },
  float = {
    width = 0.9, height = 0.9,
    layout = {                        -- recursive {weight, content} tree
      { 4, "tc" },                    -- test case list, weight 4
      { 5, { { 1, "si" }, { 1, "so" } } },  -- input/output, vertical split
      { 5, { { 1, "info" }, { 1, "eo" } } }, -- info/expected, vertical split
    },
  },
  split = {
    width = 0.3,                      -- ratio of editor width/height
    direction = "right",              -- "right"|"left"|"above"|"below"
    layout = { ... },                 -- same recursive syntax
  },
}

Style	Parameters
`float`	`width` (ratio), `height` (ratio), `layout`
`split`	`width` (ratio), `direction` (`"right"` default), `layout`

tc_ui — Judge results (panels: tc, si, so, info, eo)
tc_edit_ui — Test case editor (panels: tc, si, so)
stress_ui — Stress test viewer (panels: tc, si, so, info, eo)

Highlights

highlights = {
  windows = { Header = "#c0c0c0", Correct = "#00ff00", Warning = "orange", Wrong = "red" },
  stdio   = { Header = "#c0c0c0", Correct = "#00ff00", Warning = "orange", Wrong = "orange" },
},

Code Obfuscator

Optional pre-processing before submission (use with caution).

code_obfuscator = {
  result = ".obfuscator/$(FNAME)",
  cmd = { exec = "obfuscator_cpp", args = { "$(FABSPATH)", ".obfuscator/$(FNAME)" } },
},

📊 Platform & Language Support

Cross-platform: Windows, Linux, macOS.
Compiled languages: C, C++, Rust, Go, Java, Kotlin, C#, Pascal, Swift, Zig.
Scripting languages: Python, JavaScript (Node), TypeScript (ts-node), Lua.

If you have questions or suggestions, open an Issue or submit a PR!

Name		Name	Last commit message	Last commit date
Latest commit History 61 Commits
img		img
lua/faster-oj		lua/faster-oj
CLAUDE.md		CLAUDE.md
LICENSE		LICENSE
PLAN.md		PLAN.md
README.md		README.md
README.zh-CN.md		README.zh-CN.md

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Repository files navigation

Faster-OJ.nvim

✨ Core Features

🚀 Recommended Workflow

📦 Installation

Dependencies

Minimal Configuration (lazy.nvim)

Recommended Configuration

⌨️ Recommended Keymaps

🛠 Commands

Service

Judge & UI

Submit

Problem Management

Finder

Stress Testing

⚙️ Configuration Reference

Paths

Server

Judge

Variable Expansion

Compile & Run Commands

UI Layouts

Highlights

Code Obfuscator

📊 Platform & Language Support

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Faster-OJ.nvim

✨ Core Features

🚀 Recommended Workflow

📦 Installation

Dependencies

Minimal Configuration (lazy.nvim)

Recommended Configuration

⌨️ Recommended Keymaps

🛠 Commands

Service

Judge & UI

Submit

Problem Management

Finder

Stress Testing

⚙️ Configuration Reference

Paths

Server

Judge

Variable Expansion

Compile & Run Commands

UI Layouts

Highlights

Code Obfuscator

📊 Platform & Language Support

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