day 5 https://youtu.be/Imq-uO3d-YE

Author: tpatel

day05.mjs

@@ -0,0 +1,74 @@
+import { readFileSync } from "node:fs";
+
+const lines = readFileSync("day05.txt", { encoding: "utf-8" }) // read day??.txt content
+  .replace(/\r/g, "") // remove all \r characters to avoid issues on Windows
+  .trimEnd(); // Remove ending whitespace
+
+const [rawStacks, rawMoves] = lines.split("\n\n").map((x) => x.split("\n"));
+
+const parsedStacks = rawStacks.map((line) =>
+  [...line].filter((value, index) => index % 4 === 1)
+);
+
+const indexes = parsedStacks.pop();
+
+const stacks = {};
+
+for (const line of parsedStacks) {
+  for (let i = 0; i < line.length; i++) {
+    if (line[i] !== " ") {
+      // Add line[i] to the stack indexes[i]
+      if (!stacks[indexes[i]]) {
+        stacks[indexes[i]] = [];
+      }
+      stacks[indexes[i]].unshift(line[i]);
+    }
+  }
+}
+
+const moves = [];
+for (const move of rawMoves) {
+  const match = /move (\d+) from (\d+) to (\d+)/g.exec(move);
+  moves.push({
+    count: parseInt(match[1]),
+    from: parseInt(match[2]),
+    to: parseInt(match[3]),
+  });
+}
+
+function part1() {
+  const localStacks = JSON.parse(JSON.stringify(stacks));
+  for (const move of moves) {
+    for (let i = 0; i < move.count; i++) {
+      const crate = localStacks[move.from].pop();
+      localStacks[move.to].push(crate);
+    }
+  }
+  console.log(
+    indexes
+      .map((value) => {
+        const stack = localStacks[value];
+        return stack[stack.length - 1];
+      })
+      .join("")
+  );
+}
+
+function part2() {
+  const localStacks = JSON.parse(JSON.stringify(stacks));
+  for (const move of moves) {
+    const crates = localStacks[move.from].splice(-move.count, move.count);
+    localStacks[move.to] = localStacks[move.to].concat(crates);
+  }
+  console.log(
+    indexes
+      .map((value) => {
+        const stack = localStacks[value];
+        return stack[stack.length - 1];
+      })
+      .join("")
+  );
+}
+
+part1();
+part2();