adding day 9 super slow solution

Author: shahata

package-lock.json

@@ -15,6 +15,7 @@
   },
   "dependencies": {
     "@datastructures-js/priority-queue": "^6.3.1",
+    "@flatten-js/core": "^1.6.8",
     "@graph-algorithm/minimum-cut": "^2.0.0",
     "@shahata/inquirer-timeout-confirm-prompt": "^1.0.1",
     "chart.js": "^4.5.0",
@@ -49,4 +50,4 @@
       }
     ]
   }
-}
+}

package.json

@@ -0,0 +1,178 @@
+// import { Box, BooleanOperations, Polygon } from "@flatten-js/core";
+// const { intersect } = BooleanOperations;
+
+export function part1(input) {
+  let points = input.split("\n").map(line => {
+    let [x, y] = line.split(",").map(Number);
+    return { x, y };
+  });
+  let maxArea = 0;
+  for (let i = 0; i < points.length; i++) {
+    for (let j = i + 1; j < points.length; j++) {
+      let p1 = points[i];
+      let p2 = points[j];
+      let area = Math.abs(p1.x - p2.x + 1) * Math.abs(p1.y - p2.y + 1);
+      if (area > maxArea) {
+        maxArea = area;
+      }
+    }
+  }
+  return maxArea;
+}
+
+function connectPoints(p1, p2, grid) {
+  let xStep = p1.x < p2.x ? 1 : p1.x > p2.x ? -1 : 0;
+  let yStep = p1.y < p2.y ? 1 : p1.y > p2.y ? -1 : 0;
+  let x = p1.x;
+  let y = p1.y;
+  while (x !== p2.x || y !== p2.y) {
+    grid.set(`${y},${x}`, 1);
+    x += xStep;
+    y += yStep;
+  }
+}
+
+function findPointWithinShape(grid, height, width) {
+  for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+      x = (Math.random() * width) | 0;
+      y = (Math.random() * height) | 0;
+      if (grid.get(`${y},${x}`) === 1) continue;
+      let queue = [{ x, y }];
+      let visited = new Set();
+      let found = true;
+      while (queue.length > 0) {
+        let { x: cx, y: cy } = queue.shift();
+        let key = `${cx},${cy}`;
+        if (visited.has(key)) continue;
+        visited.add(key);
+        if (cx < 0 || cx >= width || cy < 0 || cy >= height) {
+          found = false;
+          break;
+        }
+        if (grid.get(`${cy},${cx}`) === 1) continue;
+        queue.push({ x: cx + 1, y: cy });
+        queue.push({ x: cx - 1, y: cy });
+        queue.push({ x: cx, y: cy + 1 });
+        queue.push({ x: cx, y: cy - 1 });
+      }
+      if (found) {
+        return { x, y };
+      }
+    }
+  }
+  return null;
+}
+
+function fillGrid(points, grid, height, width) {
+  for (let i = 0; i < points.length; i++) {
+    let p1 = points[i];
+    let p2 = points[(i + 1) % points.length];
+    connectPoints(p1, p2, grid);
+  }
+  let insidePoint = findPointWithinShape(grid, height, width);
+  let queue = [insidePoint];
+  let visited = new Set();
+  while (queue.length > 0) {
+    let { x: cx, y: cy } = queue.shift();
+    let key = `${cx},${cy}`;
+    if (visited.has(key)) continue;
+    visited.add(key);
+    if (grid.get(`${cy},${cx}`) === 1) continue;
+    grid.set(`${cy},${cx}`, 1);
+    queue.push({ x: cx + 1, y: cy });
+    queue.push({ x: cx - 1, y: cy });
+    queue.push({ x: cx, y: cy + 1 });
+    queue.push({ x: cx, y: cy - 1 });
+  }
+}
+
+// function test(input) {
+//   let points = input.split("\n").map(line => {
+//     let [x, y] = line.split(",").map(Number);
+//     return { x, y };
+//   });
+//   let maxArea = 0;
+//   let polygon = new Polygon(points.map(p => [p.x, p.y]));
+//   for (let i = 0; i < points.length; i++) {
+//     for (let j = i + 1; j < points.length; j++) {
+//       let a = points[i];
+//       let b = points[j];
+//       let minX = Math.min(a.x, b.x);
+//       let maxX = Math.max(a.x, b.x);
+//       let minY = Math.min(a.y, b.y);
+//       let maxY = Math.max(a.y, b.y);
+//       let box = new Box(minX, minY, maxX, maxY);
+
+//       let boxPolygon = new Polygon(box);
+//       try {
+//         let intersectionArea = intersect(polygon, boxPolygon).area();
+//         let boxArea = boxPolygon.area();
+//         if (intersectionArea === boxArea) {
+//           let area = Math.abs(a.x - b.x + 1) * Math.abs(a.y - b.y + 1);
+//           if (area > maxArea) {
+//             maxArea = area;
+//           }
+//         }
+//       } catch {
+//         //
+//       }
+//     }
+//   }
+//   return maxArea;
+// }
+
+function slow(input) {
+  let points = input.split("\n").map(line => {
+    let [x, y] = line.split(",").map(Number);
+    return { x, y };
+  });
+  let maxArea = 0;
+  for (let p of points) {
+    p.x = Math.floor(p.x / 100);
+    p.y = Math.floor(p.y / 100);
+  }
+  let maxX = Math.max(...points.map(p => p.x));
+  let maxY = Math.max(...points.map(p => p.y));
+  let grid = new Map();
+  fillGrid(points, grid, maxY + 1, maxX + 1);
+  let result;
+  for (let i = 0; i < points.length; i++) {
+    for (let j = i + 1; j < points.length; j++) {
+      let p1 = points[i];
+      let p2 = points[j];
+      let isContained = true;
+      let minX = Math.min(p1.x, p2.x);
+      let maxX = Math.max(p1.x, p2.x);
+      let minY = Math.min(p1.y, p2.y);
+      let maxY = Math.max(p1.y, p2.y);
+      for (let y = minY; y <= maxY; y++) {
+        for (let x = minX; x <= maxX; x++) {
+          if (grid.get(`${y},${x}`) !== 1) {
+            isContained = false;
+            break;
+          }
+        }
+        if (!isContained) break;
+      }
+      if (!isContained) continue;
+      let area = Math.abs(p1.x - p2.x + 1) * Math.abs(p1.y - p2.y + 1);
+      if (area > maxArea) {
+        maxArea = area;
+        result = { i, j };
+      }
+    }
+  }
+  points = input.split("\n").map(line => {
+    let [x, y] = line.split(",").map(Number);
+    return { x, y };
+  });
+  let p1 = points[result.i];
+  let p2 = points[result.j];
+  maxArea = Math.abs(p1.x - p2.x + 1) * Math.abs(p1.y - p2.y + 1);
+  return maxArea;
+}
+
+export function part2(input) {
+  return slow(input);
+}

src/2025/day09.js

@@ -0,0 +1,35 @@
+import { part1, part2 } from "./day09.js";
+import { describe, test, expect } from "vitest";
+import readInput from "../utils/read-input.js";
+
+let input = readInput(import.meta.url);
+
+describe("day09 2025", () => {
+  describe("part1", () => {
+    test("it should work for part 1 examples", () => {
+      expect(
+        part1(
+          ["7,1", "11,1", "11,7", "9,7", "9,5", "2,5", "2,3", "7,3"].join("\n"),
+        ),
+      ).toEqual(50);
+    });
+
+    test("it should work for part 1 input", () => {
+      expect(part1(input)).toEqual(4769758290);
+    });
+  });
+
+  describe("part2", () => {
+    test("it should work for part 2 examples", () => {
+      expect(
+        part2(
+          ["7,1", "11,1", "11,7", "9,7", "9,5", "2,5", "2,3", "7,3"].join("\n"),
+        ),
+      ).toEqual(24);
+    });
+
+    test("it should work for part 2 input", () => {
+      expect(part2(input)).toEqual(1588990708);
+    });
+  });
+});