Advent Of Code 2020

0-Intro.md

Advent Of Code 2020

Behold the wraith of my JS hacks.

1.js

var inputs = document.body.innerText.split(/\s+/).map((i) => parseInt(i, 10));

// loopy loopy loop
for (var i = 0; i < inputs.length; i++) {
  for (var x = 0; x < inputs.length; x++) {
    for (var y = 0; y < inputs.length; y++) {
      if (inputs[x] + inputs[i] + inputs[y] === 2020) {
        console.log(inputs[x] * inputs[i] * inputs[y]);
      }
    }
  }
}

// loopy loop
for (var i = 0; i < inputs.length; i++) {
  for (var x = 0; x < inputs.length; x++) {
    if (inputs[x] + inputs[i] === 2020) {
      console.log(inputs[x] * inputs[i]);
    }
  }
}

2.js

var inputs = document.body.innerText.split(/\r?\n/);

var valid = 0;

for (var i = 0; i < inputs.length; i++) {
  // can you do the splits like I can?
  var splits = inputs[i].split(/[\s:]/);
  var range = splits[0].split("-");
  var rangeMin = range[0];
  var rangeMax = range[1];
  var char = splits[1];
  var pass = splits[3];

  if (!pass) {
    continue;
  }

  var count = (pass.match(new RegExp(char, "g")) || []).length;

  if (count >= rangeMin && count <= rangeMax) {
    valid++;
  }
}

valid = 0;

for (var i = 0; i < inputs.length; i++) {
  // dang! more splits!
  var splits = inputs[i].split(/[\s:]/);
  var range = splits[0].split("-");
  var rangeMin = range[0] - 1;
  var rangeMax = range[1] - 1;
  var char = splits[1];
  var pass = splits[3];

  if (!pass) {
    continue;
  }

  if (pass[rangeMin] === char && pass[rangeMax] !== char) {
    valid++;
  } else if (pass[rangeMin] !== char && pass[rangeMax] === char) {
    valid++;
  }
}

3.js

var input = document.body.innerText
  .split(/\r?\n/)
  // random large number because why not
  .map((input) => input.repeat(400));

var slopeX = 0;
var slopeY = 0;
var count = 0;

// [3, 1] Stage 1 toboggan
for (var row = 0; row < input.length; row++) {
  slopeX = slopeX + 3;
  slopeY = slopeY + 1;

  if (!input[slopeY][slopeX]) {
    console.log("[3, 1] END. Total count:", count);
    break;
  }

  if (input[slopeY][slopeX] === "#") {
    count++;
  }
}

slopeX = 0;
slopeY = 0;
count = 0;

// [1, 1] Stage 2 toboggan - dang picking up speed!
for (var row = 0; row < input.length; row++) {
  slopeX = slopeX + 1;
  slopeY = slopeY + 1;

  if (!input[slopeY][slopeX]) {
    console.log("[1, 1] END. Total count:", count);
    break;
  }

  if (input[slopeY][slopeX] === "#") {
    count++;
  }
}

slopeX = 0;
slopeY = 0;
count = 0;

// [5, 1] Stage 3 toboggan - whoa slow down!
for (var row = 0; row < input.length; row++) {
  slopeX = slopeX + 5;
  slopeY = slopeY + 1;

  if (!input[slopeY][slopeX]) {
    console.log("[5, 1] END. Total count:", count);
    break;
  }

  if (input[slopeY][slopeX] === "#") {
    count++;
  }
}

slopeX = 0;
slopeY = 0;
count = 0;

// [7, 1] Stage 4 toboggan - you're going to kill us!
for (var row = 0; row < input.length; row++) {
  slopeX = slopeX + 7;
  slopeY = slopeY + 1;

  if (!input[slopeY][slopeX]) {
    console.log("[7, 1] END. Total count:", count);
    break;
  }

  if (input[slopeY][slopeX] === "#") {
    count++;
  }
}

slopeX = 0;
slopeY = 0;
count = 0;

// [1, 2] Stage 5 toboggan - red bull gives you wings!
for (var row = 0; row < input.length; row++) {
  slopeX = slopeX + 1;
  slopeY = slopeY + 2;

  if (!input[slopeY]) {
    console.log("[1, 2] END. Total count:", count);
    break;
  }

  if (input[slopeY][slopeX] === "#") {
    count++;
  }
}

Cool man, love those ideas (solve the problem on the browser) and comment code lines as well