Merge pull request #71 from Arxcis/day08/deno

Solve day 08 in deno.ts

Author: Arxcis

days/day-08/solutions/.keep

@@ -0,0 +1,93 @@
+type Instruction = {
+  op: "nop" | "acc" | "jmp";
+  arg: number;
+};
+
+const input = (await Deno.readTextFile("/dev/stdin"))
+  .split("\n")
+  .slice(0, -1);
+
+const instructions = input
+  .map((line) => line.split(" "))
+  .map(([op, arg]) => ({ op, arg: parseInt(arg) })) as Instruction[];
+
+/** --- Part 1 --- */
+{
+  let ipTracker = new Set<number>([]);
+  let accumulator = 0;
+  let instructionPointer = 0;
+
+  while (!ipTracker.has(instructionPointer)) {
+    ipTracker.add(instructionPointer);
+
+    const { op, arg } = instructions[instructionPointer];
+
+    switch (op) {
+      case "nop":
+        instructionPointer += 1;
+        break;
+      case "acc":
+        instructionPointer += 1;
+        accumulator += arg;
+        break;
+      case "jmp":
+        instructionPointer += arg;
+        break;
+    }
+  }
+  console.log(`${accumulator}`);
+}
+
+/** --- Part 2 --- */
+{
+  let ipTracker = new Set<number>([]);
+  let accumulator = 0;
+  let instructionPointer = 0;
+  let modIndex = 0;
+
+  for (
+    let modStep = instructions.findIndex(({ op }) =>
+      op === "nop" || op === "jmp"
+    );
+    modStep !== -1 && instructionPointer < instructions.length;
+    modStep = instructions.slice(modIndex + 1).findIndex(({ op }) =>
+      op === "nop" || op === "jmp"
+    ), modIndex += 1 + modStep
+  ) {
+    ipTracker = new Set<number>([]);
+    accumulator = 0;
+    instructionPointer = 0;
+
+    const { op: modOp, arg: modArg } = instructions[modIndex];
+
+    const modifiedInstructions = [
+      ...instructions.slice(0, modIndex),
+      { arg: modArg, op: modOp === "nop" ? "jmp" : "nop" },
+      ...instructions.slice(modIndex + 1),
+    ];
+
+    while (
+      !ipTracker.has(instructionPointer) &&
+      instructionPointer < instructions.length
+    ) {
+      ipTracker.add(instructionPointer);
+
+      const { op, arg } = modifiedInstructions[instructionPointer];
+
+      switch (op) {
+        case "nop":
+          instructionPointer += 1;
+          break;
+        case "acc":
+          instructionPointer += 1;
+          accumulator += arg;
+          break;
+        case "jmp":
+          instructionPointer += arg;
+          break;
+      }
+    }
+  }
+
+  console.log(`${accumulator}`);
+}

days/day-08/solutions/day08.ts

@@ -6,4 +6,5 @@ D=$(dirname $(realpath $0))
 
 echo ""
 echo "--- Day 8: Handheld Halting ---"
+$D/../../languages/deno.sh   $D/input.txt $D/output.txt $D/solutions/day08.ts
 echo ""