day 3 jesus

1 files changed, 96 insertions, 0 deletions

diff --git a/aoc_2023/day-03/part_2.ts b/aoc_2023/day-03/part_2.ts
new file mode 100644
index 0000000..4f36cb2
--- /dev/null
+++ b/aoc_2023/day-03/part_2.ts
@@ -0,0 +1,96 @@
+import { JSONSet, Vec2 } from "@/utils";
+
+const isNumeric = (symbol: string) => symbol <= "9" && symbol >= "0";
+
+export const main = async (lines: string[]): Promise<number | string> => {
+  const adjacentPoints: (Vec2 & { ratio: number })[] = [];
+
+  let ratioId = 0;
+
+  const dimy = lines.length;
+  for (let y = 0; y < lines.length; y++) {
+    const dimx = lines[y].length;
+    for (let x = 0; x < dimx; x++) {
+      const symbol = lines[y][x];
+      if (symbol === "*") {
+        ratioId++;
+        for (let dy = -1; dy <= 1; dy++) {
+          for (let dx = -1; dx <= 1; dx++) {
+            const newX = dx + x;
+            const newY = dy + y;
+            if (
+              !(dy === dx && dy === 0) &&
+              newX >= 0 &&
+              newX < dimx &&
+              newY < dimy &&
+              newY >= 0
+            ) {
+              adjacentPoints.push({
+                x: x + dx,
+                y: y + dy,
+                ratio: ratioId,
+              });
+            }
+          }
+        }
+      }
+    }
+  }
+
+  const visitedPoints: JSONSet<Vec2> = new JSONSet();
+  const ratioNums: Map<number, number[]> = new Map();
+  for (const { x, y, ratio } of adjacentPoints) {
+    const symbol = lines[y][x];
+    if (!isNumeric(symbol)) continue;
+
+    let num = "";
+    if (!visitedPoints.has({ x, y })) {
+      let x_i = x;
+      while (x_i >= 0 && isNumeric(lines[y][x_i])) {
+        x_i--;
+      }
+      x_i = Math.max(0, x_i + 1);
+
+      while (x_i < lines[y].length && isNumeric(lines[y][x_i])) {
+        num += lines[y][x_i];
+        visitedPoints.add({ x: x_i, y });
+
+        x_i++;
+      }
+    }
+
+    if (num.trim() !== "") {
+      const n = parseInt(num.trim());
+      const curr = ratioNums.get(ratio) ?? [];
+      ratioNums.set(ratio, curr.concat([n]));
+    }
+  }
+
+  return Array.from(ratioNums.keys())
+    .map((ratioId) => {
+      const arr = ratioNums.get(ratioId)!;
+      if (arr.length > 1) {
+        return arr.reduce((acc, x) => acc * x, 1);
+      }
+      return 0;
+    })
+    .reduce((acc, x) => acc + x, 0);
+};
+
+//
+
+const isrun = process.argv.length > 1 && process.argv[1] === import.meta.path;
+if (isrun) {
+  const file = Bun.file("./problem.txt");
+  const text = await file.text();
+  const lines = text.split("\n").filter((x) => x && x.length);
+
+  console.log("=== COMPUTATION ===\n");
+
+  const answer = await main(lines);
+
+  console.log("\n=== /COMPUTATION ===\n");
+
+  console.log("=== ANSWER TO P2 ===");
+  console.log(answer);
+}