day-08

Author: belaczek

.deno/gen/file/home/runner/adventOfCode2020/day-08/index.ts.js

@@ -0,0 +1 @@
+{"source_path":"/home/runner/adventOfCode2020/day-08/index.ts","version_hash":"108577a9380b86b7cf6de2d6b848c6361c53384fa5d027c55bdbd3f7ffce9b6c"}

.deno/gen/file/home/runner/adventOfCode2020/day-08/index.ts.js.map

@@ -1 +1 @@
-{"deps":["file:///home/runner/adventOfCode2020/day-07/index.ts","file:///home/runner/adventOfCode2020/index.ts","file:///home/runner/adventOfCode2020/day-07/index.ts","file:///home/runner/adventOfCode2020/index.ts"],"version_hash":"7fbd210ebec11f65a97190ef900795c4b8da3805af3f5a1b8d1d272556b292ca"}
+{"deps":["file:///home/runner/adventOfCode2020/day-08/index.ts","file:///home/runner/adventOfCode2020/day-08/index.ts","file:///home/runner/adventOfCode2020/index.ts","file:///home/runner/adventOfCode2020/index.ts"],"version_hash":"7fbd210ebec11f65a97190ef900795c4b8da3805af3f5a1b8d1d272556b292ca"}

.deno/gen/file/home/runner/adventOfCode2020/day-08/index.ts.meta

@@ -1 +1 @@
-{"source_path":"/home/runner/adventOfCode2020/index.ts","version_hash":"8245267391dbd10090eb5d5e49dad20c2c8e2cab880cb7a480109ef8cfee9b62"}
+{"source_path":"/home/runner/adventOfCode2020/index.ts","version_hash":"646ea2b3bea045f7f4c67b681820d8fff9a91b69a2d9af23b7929ce0249c307f"}

.deno/gen/file/home/runner/adventOfCode2020/index.ts.graph

@@ -0,0 +1,130 @@
+const input = Deno.readTextFileSync("./day-08/input.txt")
+const rows = input.split('\n')
+
+type Opertaion = 'nop' | 'acc' | 'jmp'
+
+interface Instruction {
+  operation: Opertaion
+  argument: number,
+  visited: boolean
+}
+
+const stage1 = () => {
+  const instructions: Instruction[] = rows.map(row => {
+    const [operation, argument] = row.split(" ")
+    return {
+      operation: operation as Opertaion, argument: Number(argument), visited: false
+    }
+  })
+
+  let accumulator = 0
+  let pointer = 0
+
+  while (!instructions[pointer].visited) {
+    const instruction = instructions[pointer]
+    const { operation, argument, visited } = instruction
+
+    instruction.visited = true
+
+    switch (operation) {
+      case "acc":
+        accumulator += argument
+        pointer++
+        break
+      case "jmp":
+        pointer += argument
+        break
+      case "nop":
+        pointer++
+        break
+    }
+  }
+
+  return accumulator
+}
+
+const run = (instructions: Instruction[]) => {
+  let accumulator = 0
+  let prevPointer = 0
+  let pointers = [0]
+
+  for (const pointer of pointers) {
+    const instruction = instructions[pointer]
+
+    if (!instruction) {
+      return {
+        accumulator
+      }
+    }
+
+    const { operation, argument, visited } = instruction
+
+    if (visited) {
+      return {
+        accumulator,
+        badInstruction: pointer
+      }
+    }
+
+    instruction.visited = true
+    prevPointer = pointer
+
+    switch (operation) {
+      case "acc":
+        accumulator += argument
+        pointers.push(pointer + 1)
+        break
+      case "jmp":
+        pointers.push(pointer + argument)
+        break
+      case "nop":
+        pointers.push(pointer + 1)
+        break
+      default:
+        pointers.push(pointer + 1)
+        break
+    }
+  }
+
+  return { accumulator }
+}
+
+const parseRow = (row: string) => {
+  const [operation, argument] = row.split(" ")
+  return {
+    operation: operation as Opertaion, argument: Number(argument), visited: false
+  }
+}
+
+const stage2 = () => {
+  const instructions: Instruction[] = rows.map(parseRow)
+
+  let accumulator = -1
+
+  instructions.forEach((instruction, i) => {
+    // this is ugly, duplicate, messy and stuff, but whatever 🙂
+    if (instruction.operation === "jmp") {
+      const fixedInstructions = rows.map(parseRow)
+      fixedInstructions[i].operation = 'nop'
+      const res = run(fixedInstructions)
+
+      if (res.badInstruction === undefined) {
+        accumulator = res.accumulator
+      }
+    } else if (instruction.operation === "nop") {
+      const fixedInstructions = rows.map(parseRow)
+      fixedInstructions[i].operation = 'jmp'
+      const res = run(fixedInstructions)
+
+      if (res.badInstruction === undefined) {
+        accumulator = res.accumulator
+      }
+    }
+  })
+
+  return accumulator
+}
+
+
+// console.log(stage1())
+console.log(stage2())