AOC 2019 answer

d2.js

const parse = text => text.split(",").map(el => +el);
let backupMemory = parse(input);
const optCode = number => (a, b) =>
  ({
    1: a + b,
    2: a * b,
    99: null
  }[number]);
const readFromMemory = (memory, location) => memory[location];
const writeToMemory = (memory, location, value) => (memory[location] = value);
const executeInstruction = (memory, place) =>
  writeToMemory(
    memory,
    memory[place + 3],
    optCode(memory[place])(
      readFromMemory(memory, memory[place + 1]),
      readFromMemory(memory, memory[place + 2])
    )
  );
runP1 = (noun, verb) => {
  let [first, second, third, ...instructions] = backupMemory.slice(0);
  let instructionSet = [first, noun, verb, ...instructions];
  console.log(instructionSet);
  instructionSet.map((addr, index) =>
    index % 4 === 0 ? executeInstruction(instructionSet, index) : null
  );
  console.log(instructionSet);
  return instructionSet;
};
runP2 = (find = 19690720) => {
  for (
    noun = 0, verb = 0;
    noun <= 99 && verb <= 99;
    noun >= 99 ? (verb++, (noun = 0)) : noun++
  ) {
    check = runP1(noun, verb);
    if (check[0] === find) {
      console.log(noun, verb, 100 * noun + verb);
      break;
    }
  }
};