Solve 2024-14

2024/14/index.ts

@@ -0,0 +1,109 @@
+import { multArray } from '../../utils/array.ts';
+import {
+  calculateVariance,
+  type Coordinate,
+  CoordinateIndices,
+  type Coordinates,
+  type CoordinateSides,
+  isCoordinateEqual
+} from '../../utils/coordinates.ts';
+
+function mod(x: number, m: number) {
+  return ((x % m) + m) % m;
+}
+
+export function solveFirst(
+  input: string,
+  xMax = 101,
+  yMax = 103,
+  iterations = 100
+): number {
+  const match = input.matchAll(/^p=(-?\d*),(-?\d*) v=(-?\d*),(-?\d*)$/gm);
+
+  const matches = Array.from(match, (m) => ({
+    p: m.slice(1, 3).map(Number) as Coordinate,
+    v: m.slice(3, 5).map(Number) as Coordinate
+  }));
+
+  const finalPositions = matches.map(
+    (p) =>
+      [
+        mod(p.p[0] + p.v[0] * iterations, xMax),
+        mod(p.p[1] + p.v[1] * iterations, yMax)
+      ] as Coordinate
+  );
+
+  const centerX = Math.floor(xMax / 2);
+  const centerY = Math.floor(yMax / 2);
+
+  const sumQuadrants = finalPositions.reduce(
+    (quads, position) => {
+      const [x, y] = position;
+      if (x < centerX) {
+        if (y < centerY) {
+          quads[0]++;
+        } else if (y > centerY) {
+          quads[3]++;
+        }
+      } else if (x > centerX) {
+        if (y < centerY) {
+          quads[1]++;
+        } else if (y > centerY) {
+          quads[2]++;
+        }
+      }
+      return quads;
+    },
+    [0, 0, 0, 0]
+  );
+
+  return multArray(sumQuadrants);
+}
+
+export function solveSecond(input: string, xMax = 101, yMax = 103): number {
+  const match = input.matchAll(/^p=(-?\d*),(-?\d*) v=(-?\d*),(-?\d*)$/gm);
+
+  const matches = Array.from(match, (m) => ({
+    p: m.slice(1, 3).map(Number) as Coordinate,
+    v: m.slice(3, 5).map(Number) as Coordinate
+  }));
+
+  for (let i = 0; i < xMax * yMax; i++) {
+    const finalPositions = matches.map(
+      (p) =>
+        [
+          mod(p.p[0] + p.v[0] * i, xMax),
+          mod(p.p[1] + p.v[1] * i, yMax)
+        ] as Coordinate
+    );
+    const oX = calculateVariance(finalPositions, CoordinateIndices.x);
+
+    const oY = calculateVariance(finalPositions, CoordinateIndices.y);
+    calculateVariance([[0, 1, 2]] as CoordinateSides, CoordinateIndices.side);
+
+    // hard coded, ups
+    // would be better to find the lowest oX = lX in 0-maxX and lowest oY = lY in 0-maxY
+    // then solve yMax * n + lY = xMax * (n+1) + lX, for n
+    // IDK why x+1 tho
+    if (oX < 600 && oY < 600) {
+      if (process.env.NODE_ENV === 'production') {
+        console.log(i, oX.toFixed(0), oY.toFixed(0));
+        renderRobots(finalPositions, xMax, yMax);
+      }
+      return i;
+    }
+  }
+
+  return 0;
+}
+
+function renderRobots(coords: Coordinates, xMax: number, yMax: number) {
+  for (let y = 0; y < yMax; y++) {
+    const row = new Array(xMax)
+      .fill(' ')
+      .map((_, x) =>
+        coords.some((c) => isCoordinateEqual(c, [x, y])) ? '*' : ' '
+      );
+    console.log(row.join(''));
+  }
+}