AoC-2017-day5.js

function part1(str) {
  let numbers = str.split("\n").map(num => parseInt(num));
  let count = 0;
  let nextIndex = 0;
  let mazeSize = numbers.length;
  while (nextIndex < mazeSize) {
    count++;
    const currentIndex = nextIndex;
    nextIndex = numbers[currentIndex] + currentIndex;
    numbers[currentIndex] = numbers[currentIndex] + 1;
  }
  return count;
}

function part2(str) {
  let numbers = str.split("\n").map(num => parseInt(num));
  let count = 0;
  let nextIndex = 0;
  let mazeSize = numbers.length;
  while (nextIndex < mazeSize) {
    count++;
    const currentIndex = nextIndex;
    nextIndex = numbers[currentIndex] + currentIndex;
    numbers[currentIndex] =
      numbers[currentIndex] + (numbers[currentIndex] >= 3 ? -1 : 1);
  }
  return count;
}

const input = require("fs").readFileSync("day5-input.txt", "UTF-8");

console.log("Part1:", part1(input));
console.log("Part2:", part2(input));