2022 - Day 5

2022-12-05 13:41:24 +01:00
parent 68460a6af7
commit 83d5f3758e
5 changed files with 713 additions and 0 deletions
@@ -0,0 +1,83 @@
+const sample = await Deno.readTextFile("sample.txt");
+const input = await Deno.readTextFile("input.txt");
+
+const parseStack = (stackData: string): string[][] => {
+  const rotateMatrix = (matrix: string[][]): string[][] =>
+    matrix[0].map((_, index) =>
+      matrix
+        .map((row2) => row2[index].trim())
+        .reverse()
+        .filter(Boolean)
+    );
+
+  return rotateMatrix(
+    stackData
+      .split("\n")
+      // Filter out last line and empty lines
+      .filter((line, index, arr) => Boolean(line) && index < arr.length - 1)
+      .map((line) =>
+        line
+          .split("")
+          .reduce((r, v, i) => {
+            const p = Math.floor(i / 4);
+            r[p] = r[p] || [];
+            r[p].push(v);
+            return r;
+          }, [] as string[][])
+          .map((row) => row[1])
+      )
+  );
+};
+
+const parseMoves = (
+  moveData: string
+): { amount: number; from: number; to: number }[] => {
+  return moveData
+    .split("\n")
+    .filter(Boolean)
+    .map(
+      (line): number[] =>
+        line
+          .match(/move\ (\d+)\ from\ (\d+)\ to\ (\d+)/)
+          ?.slice(1)
+          .map((v) => parseInt(v, 10)) || []
+    )
+    .map(([amount, from, to]) => ({ amount, from: from - 1, to: to - 1 }));
+};
+
+const solvePart1 = (data: string): string => {
+  const [stackData, moveData] = data.split("\n\n");
+  const stacks = parseStack(stackData);
+  const moves = parseMoves(moveData);
+  return moves
+    .reduce((stack, move) => {
+      const length = stack[move.from].length;
+      stack[move.to] = stack[move.to].concat(
+        stack[move.from].splice(length - move.amount, length).reverse()
+      );
+      return stack;
+    }, stacks)
+    .map((stack) => stack.pop())
+    .join("");
+};
+
+console.log("Sample:", solvePart1(sample));
+console.log("Input", solvePart1(input));
+
+const solvePart2 = (data: string): string => {
+  const [stackData, moveData] = data.split("\n\n");
+  const stacks = parseStack(stackData);
+  const moves = parseMoves(moveData);
+  return moves
+    .reduce((stack, move) => {
+      const length = stack[move.from].length;
+      stack[move.to] = stack[move.to].concat(
+        stack[move.from].splice(length - move.amount, length)
+      );
+      return stack;
+    }, stacks)
+    .map((stack) => stack.pop())
+    .join("");
+};
+console.log("Sample:", solvePart2(sample));
+console.log("Input", solvePart2(input));