Advent of Code - 2019 - Day 2

solution.js

// part 1
const array = $0.textContent.split(',').map(Number);

array[1] = 12;
array[2] = 2;

let i = 0;

while (i < array.length) {
  const current = array[i];
  if (current === 99) break;
  if (current === 1) {
    array[array[i+3]] = array[array[i+1]] + array[array[i+2]];
    i += 4;
  }

  if (current === 2) {
    array[array[i+3]] = array[array[i+1]] * array[array[i+2]];
    i += 4;
  }
}