day 17 https://youtu.be/MTTnnqXVIso

day17.js

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+const fs = require("fs");
+
+const line = fs
+  .readFileSync("day17.txt", { encoding: "utf-8" }) // read day??.txt content
+  .trim();
+
+const target = line.match(
+  /target area: x=(?<xMin>-?\d+)..(?<xMax>-?\d+), y=(?<yMin>-?\d+)..(?<yMax>-?\d+)/
+).groups;
+
+function simulate({ vx, vy, target }) {
+  const steps = [];
+  let x = 0;
+  let y = 0;
+  while (x < target.xMax && y > target.yMin) {
+    steps.push({ x, y });
+    x += vx;
+    y += vy;
+    if (vx > 0) {
+      vx--;
+    }
+    if (vx < 0) {
+      vx++;
+    }
+    vy--; //gravity
+    if (
+      x >= target.xMin &&
+      x <= target.xMax &&
+      y >= target.yMin &&
+      y <= target.yMax
+    ) {
+      steps.push({ x, y });
+      return steps;
+    }
+  }
+}
+
+function part1() {
+  let maxY = 0;
+  for (let vx = 0; vx < target.xMax; vx++) {
+    for (let vy = 1000; vy >= 0; vy--) {
+      const steps = simulate({ vx, vy, target });
+      if (steps) {
+        let max = Math.max(...steps.map((p) => p.y));
+        if (max > maxY) {
+          maxY = max;
+        }
+      }
+    }
+  }
+  console.log(maxY);
+}
+
+part1();
+
+function part2() {
+  let total = 0;
+  for (let vx = 1; vx <= target.xMax; vx++) {
+    for (let vy = 1000; vy >= target.yMin; vy--) {
+      const steps = simulate({ vx, vy, target });
+      if (steps) {
+        total++;
+      }
+    }
+  }
+  console.log(total);
+}
+
+part2();

day17.txt

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+target area: x=150..193, y=-136..-86