v6: SortCore step-generator engine, 4 new algorithms, complexity profiler

CHANGELOG.md

@@ -2,6 +2,30 @@
 
 All notable changes to Algo Lab (Algorithm Visualizer).
 
+## [2026-08-22] — v6 Sorting Core
+
+### Added
+- **Four new sorting algorithms**: Comb Sort, Gnome Sort, Cycle Sort (provably minimal
+  writes — great for the writes metric), and a simplified TimSort (insertion-sorted
+  minruns + merge passes with the already-ordered shortcut)
+- **`sorting-core.js`** — every sorting algorithm now lives in one dependency-free
+  module as a pure step generator (works in the browser as `SortCore` and in Node via
+  `require`). The page, the tests, and the profiler all consume the same op stream.
+- **Complexity Profiler** — one click benchmarks all 14 algorithms at
+  n = 16, 32, 64, 128, 256, 512 on the current dataset shape, draws a log-log chart,
+  and reports each algorithm's measured growth exponent next to its theoretical class
+- **47 sorting unit tests** (`node --test tests/sorting.test.js`): correctness on every
+  dataset shape and edge case, stability proofs via tagged keys, cycle sort's ≤ n write
+  bound and zero-writes-on-sorted property, exact bubble counts on reversed input, and
+  exponent-estimator checks that separate the quadratic sorts from the linearithmic ones
+
+### Changed
+- `SortRunner` no longer hardcodes algorithm logic — it animates the `SortCore`
+  operation stream (compare / swap / write / touch / counts / mark ops), which keeps
+  metrics, narration, heatmap, sound, and step mode identical across all algorithms
+- Tournament, race mode, and quiz automatically include the four new algorithms
+- Service worker cache bumped to v6 and now precaches `sorting-core.js`
+
 ## [2026-08-20] — v5 Path Lab
 
 ### Added

README.md

@@ -4,10 +4,10 @@ An interactive teaching lab built with pure HTML, CSS, and vanilla JavaScript 
 
 Two labs share the same chrome, theme, and sound toggle:
 
-- **Sort Lab** (`index.html`) — 10 sorting algorithms
+- **Sort Lab** (`index.html`) — 14 sorting algorithms + empirical complexity profiler
 - **Path Lab** (`pathfinding.html`) — 6 pathfinding algorithms + maze generators
 
-![Algorithms](https://img.shields.io/badge/sort-10-blue) ![Pathfinding](https://img.shields.io/badge/path-6-indigo) ![PWA](https://img.shields.io/badge/PWA-offline-purple)
+![Algorithms](https://img.shields.io/badge/sort-14-blue) ![Pathfinding](https://img.shields.io/badge/path-6-indigo) ![PWA](https://img.shields.io/badge/PWA-offline-purple)
 
 ## Running
 
@@ -28,12 +28,16 @@ macOS: `open index.html` · Linux: `xdg-open index.html`
 Pathfinding algorithms and maze generators are covered by Node’s built-in test runner (no packages to install):
 
 ```bash
-node --test tests/pathfinding.test.js
+node --test tests/sorting.test.js tests/pathfinding.test.js
 ```
 
+Sorting coverage includes correctness on every dataset shape, stability proofs for the
+stable algorithms (via tagged keys), cycle sort's ≤ n write bound, and sanity checks on
+the complexity profiler's exponent estimator.
+
 ## Sort Lab
 
-### Algorithms (10)
+### Algorithms (14)
 
 | Algorithm | Best | Average | Worst | Stable | In-place | Memory |
 |-----------|------|---------|-------|--------|----------|--------|
@@ -47,6 +51,13 @@ node --test tests/pathfinding.test.js
 | Radix | O(nk) | O(nk) | O(nk) | Yes | No | O(n + k) |
 | Counting | O(n + k) | O(n + k) | O(n + k) | Yes | No | O(k) |
 | Cocktail Shaker | O(n) | O(n²) | O(n²) | Yes | Yes | O(1) |
+| Comb | O(n log n) | O(n²/2ᵖ) | O(n²) | No | Yes | O(1) |
+| Gnome | O(n) | O(n²) | O(n²) | Yes | Yes | O(1) |
+| Cycle | O(n²) | O(n²) | O(n²) | No | Yes | O(1) |
+| TimSort (simplified) | O(n) | O(n log n) | O(n log n) | Yes | No | O(n) |
+
+All fourteen are implemented once, as pure step generators in `sorting-core.js` —
+the page animates the operation stream, tests and the profiler consume it headlessly.
 
 ### Dataset generators
 
@@ -62,7 +73,10 @@ Random · Sorted · Nearly Sorted · Reversed · Few Unique · Sawtooth · Custo
 - Presentation Mode
 - Access heatmap + operations sparkline
 - Algorithm recommender
-- Benchmark tournament (all 10) with comparison matrix
+- Benchmark tournament (all 14) with comparison matrix
+- **Complexity Profiler** — measures total operations at n = 16…512, plots every
+  algorithm on a log-log chart, and fits the empirical growth exponent (the slope)
+  so you can watch bubble sort measure ≈ n² while counting sort measures ≈ n¹
 - Learning cards (trivia + use cases)
 - Run history (last 8, `localStorage` key `sortLabHistory`)
 - Share URL, CSV export, copy summary
@@ -124,9 +138,11 @@ algorithm-visualiser/
 ├── index.html              # Sort Lab
 ├── pathfinding.html        # Path Lab
 ├── style.css               # Shared theme + path grid
-├── script.js               # Sort Lab app
+├── script.js               # Sort Lab app (rendering, metrics, chrome)
+├── sorting-core.js         # Sorting step generators + profiler (browser + Node)
 ├── pathfinding.js          # Path Lab UI
 ├── pathfinding-core.js     # Search + mazes (browser + Node)
+├── tests/sorting.test.js
 ├── tests/pathfinding.test.js
 ├── sw.js                   # Service worker
 ├── manifest.json           # PWA manifest
@@ -135,7 +151,7 @@ algorithm-visualiser/
 └── README.md
 ```
 
-`pathfinding-core.js` exports `PathCore` in the browser and `module.exports` in Node.
+`sorting-core.js` and `pathfinding-core.js` export `SortCore` / `PathCore` in the browser and `module.exports` in Node.
 
 ## License
 

index.html

@@ -54,6 +54,10 @@ <h2 class="panel-title">Controls</h2>
               <option value="radix">Radix Sort</option>
               <option value="counting">Counting Sort</option>
               <option value="cocktail">Cocktail Shaker Sort</option>
+              <option value="comb">Comb Sort</option>
+              <option value="gnome">Gnome Sort</option>
+              <option value="cycle">Cycle Sort</option>
+              <option value="tim">TimSort (simplified)</option>
             </select>
           </div>
 
@@ -73,6 +77,10 @@ <h2 class="panel-title">Controls</h2>
               <option value="radix">Radix Sort</option>
               <option value="counting">Counting Sort</option>
               <option value="cocktail">Cocktail Shaker Sort</option>
+              <option value="comb">Comb Sort</option>
+              <option value="gnome">Gnome Sort</option>
+              <option value="cycle">Cycle Sort</option>
+              <option value="tim">TimSort (simplified)</option>
             </select>
           </div>
 
@@ -137,7 +145,8 @@ <h2 class="panel-title">Controls</h2>
             <button id="resetBtn" class="btn btn-secondary" title="Shortcut: R">Reset</button>
           </div>
 
-          <button id="tournamentBtn" type="button" class="btn btn-accent btn-full" title="Run all 10 algorithms on current data">🏆 Benchmark Tournament</button>
+          <button id="tournamentBtn" type="button" class="btn btn-accent btn-full" title="Run all 14 algorithms on current data">🏆 Benchmark Tournament</button>
+          <button id="profilerBtn" type="button" class="btn btn-accent btn-full" title="Measure operation growth across input sizes">📈 Complexity Profiler</button>
 
           <p class="shortcut-hint">Space pause · S start · G generate · R reset · Esc exit present</p>
         </section>
@@ -178,6 +187,14 @@ <h2 class="panel-title">Tournament Leaderboard</h2>
           <div id="leaderboard" class="leaderboard-wrap"></div>
         </section>
 
+        <section class="panel" id="profilerPanel" hidden>
+          <h2 class="panel-title">Complexity Profiler</h2>
+          <p class="panel-sub">Empirical operation growth — log-log, slope &asymp; exponent</p>
+          <canvas id="profilerChart" class="profiler-chart" width="640" height="320" aria-label="Log-log chart of operations versus input size for every algorithm"></canvas>
+          <p id="profilerStatus" class="profiler-status" aria-live="polite"></p>
+          <div id="profilerTable" class="matrix-wrap"></div>
+        </section>
+
         <section class="panel" id="comparisonPanel" hidden>
           <h2 class="panel-title">Comparison Matrix</h2>
           <p class="panel-sub">Theoretical vs actual performance (last tournament)</p>
@@ -264,6 +281,7 @@ <h3>Race</h3>
   <div id="toast" class="toast" role="status" aria-live="polite"></div>
   <div id="a11yAnnouncer" class="sr-only" aria-live="assertive" aria-atomic="true"></div>
 
+  <script src="sorting-core.js"></script>
   <script src="script.js"></script>
 </body>
 </html>