Advent of Code

1.js

const input = "(((())))()((((((((())()(()))(()((((()(()(((()((()((()(()()()()()))(((()(()((((((((((())(()()((())()(((())))()(()(()((()(()))(()()()()((()((()(((()()(((((((()()())()((((()()(((((()(())()(())((())()()))()(((((((())(()())(()(((())(()))((())))(()((()())))()())((((())))(()(((((()(())(((()()((()((()((((((((((())(()())))))()))())()()((((()()()()()()((((((())())(((()())()((()()(((()()()))(((((()))(((()(()()()(()(()(((())()))(()(((()((())()(()())())))((()()()(()()(((()))(((()((((()(((((()()(()())((()())())(()((((((()(()()))((((()))))())((())()()((()(()))))((((((((()))(()()(((())())(())()((()()()()((()((()((()()(((())))(()((())()((((((((()((()(()()(((())())())))(())())))()((((()))))))())))()()))()())((()())()((()()()))(()()(((()(())((((())())((((((((()()()()())))()()()((((()()))))))()((((()(((()))(()()())))((()()(((()))()()())())(((())((()()(())()()()(((())))))()())((()))()))((())()()())()())()()(()))())))())()))(())((()(())))(()(())(()))))(()(())())(()(())(()(()))))((()())()))()((((()()))))())))()()())((())()((()()()))()(((()(()))))(())()()))(((()())))))))))(((())))()))())()))))()()(((())))))))()(()()(()))((()))))((())))((()((())))())))()()(()))())()(()((()())(()(()()())())(()()))()))))(()())()()))()()()()))(()(()(()))))))()(()))()))()()(()((())(()(())))()(((())(())())))))()(()(()))))()))(()()()(())()(()(())))()))))()()(((((())))))())()())())())()())()))))()))))))))())()()()()()()())))()))((())()))())))()((())()))))()))())))))))())()()()))()()(()((((()(((((((()(())((()())((()()))()))))(())))()()()(())((())()())))(())))(())))(((()()))()(())(((()(()))((())))())()))((((()))())()))))))))()(())())))(()))()(()()))())()()(())())))())()()(()())))()((()())(()(())(())))))))))))))(()))))()))))))()()())(()(((((()(()())))())()))(()))()))(()()))()())(()))())()(())((()()))))))())))())()(((())))(()(()))()()))()(()))))))((()())(()))))))()())))()()))))))))((((((((()()()(()))))))()())))())))()()((())()))((())(())))())())))()()()((()((()(())))())()(())))))))))()())))()()()()()()))()))((())())(()(()))))))(()()))()))(())))()))))))))))))(()))))))))()))))()))()())()))()()))))))()))))((()))))(()))())()(())))(()())((((()())))()))))(()))()(()()(())))))())))))()))))))())))())))))())))())())))())(()))))(())()(())))())()))((()()))))))())))((())))))))())))(())))))()()())))))())))))()))))))()))()()()(()(((()())())())(()))())))))((()(())(()))))))))(())))()()()())())(()))))()()()))()))())())())()(())))()(((()((((())))))))()))))))))))))))))))))((())()())(()))))()()))))))(()()(())())))())))((())))((())))))))))))))()))))()(()))))))())))))()))(()()())(()())))))))))()))))))(())))))()()))()())(((())))()))(()))))))))(())())))())))())())())()()))((())()(())()())()))()())(())(()))))()())))(()(((()))))))()(()())()()()))()))))))))()()()(())()())()(((((()))()())())(()))))()()()(())))())))()((()())))(()))())()(()())())(()))()()))((()()))((()()()()())))(())()))(()(())))((()()))))))))())))))))())()()))))))))))))))))(())()(())(())()())())()))()(()))))())())))))()())()(()))()()(())))(())())))))(()))))))))))))))())())(())(())))(((()))()))))())((())(()))())))))))())))))())))()))()))))))))))))())()))))()))))((()))(())))()(())))(())()))()))())))())))))))()(()())())))()()())))(())))))(()))))))))))))(()))()))()))())))(((()()()(())((()())))()())(((()))(())()))((()()()())))())(())(()))))()(((((())))(()))())())))))))((((()()()))())())()(()(()())))))))))()())())))(())))()())(((()(())())()()))())())))))))((()())((()()(()))(()(())))()))()))(()))(()))()()(()(((())((((()))()(()))((())()(()(()())()(()))()())))))(()))()))())()())))())))(())))((())(()())))))()))(())(()))()())()(()()((()(()))))))()(())(()())(())()))(((())()))(()()(()()()))))(()(())))()))))())))))())(()()()()()()(((())))(()()))()((())(((((()()())))(()))(()))()()))(((())())()(((()()()()))))(()))(())())))()())(()()())())))))))()))))((())))()())(()))(()(()))())))))())(())))))()()())())()))()()(())))(()))(())((((((())(()))(()))())()))(()()(())))()))(()()))()))()(())))(())))((()(()))(())()()())())))(((()()())(())()))))))()(((()(((((()()(((())(())))())()((()))))((()())()(())(((())))(((()((()(()(()))(()()))())(()))(())(())))()))))))((((()))()((((()(()))()))()()))))()(()(()))()(()((()(((()(()()(((()))))()(((()(()(()(((()(()())())()()(()(()())())(()((((())(()))()))(((((()()())(())()((()()())))()()(((()()))()((((((((()(())))())((()))))(())))(()))))((()((((()()(())(((((()))(((((((((((((()())))((((()(((()((())())()))((()))()(()()((()()()()(()()(()(()(((())()(()((((((()((()()((())()((((()((()()(()()())((()()()((()((())()(()(((()((())((((())(()))((()(()))(()())()((((((((()(((((((((((()))(()(((()(()()()((((())((())()())()))(())((())(()))(((()((()(())))(()))))((()()))))((((()(()(()())(()(())((((((((()((((()((()(((((()))())()(()))(()()((()(())(((((()(())()(((((()()))))))()(((())()(()()((((())()((())((()(((())(((()))((()()((((()(())))))((()((((()((()((()(((())((()))(((((((()(((()((((((((())()))((((())(((((()((((((((()(((()((()(((()()(((()((((((()()(()((((((((()()(()(()(())((((()())()))))(((()))((((())((((()())((()(())()((()((((((()(((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const directionActions = { '(': floor => floor + 1, ')': floor => floor - 1 }
const [endedOnFloor, enteredBasementAtPosition] = input
  .split('')
  .reduce(([currentFloor, enteredBasementAtPosition], direction, index) => {
    let nextFloor = directionActions[direction](currentFloor);
    
    enteredBasementAtPosition = (nextFloor === -1 && enteredBasementAtPosition === undefined)
      ? index + 1 : enteredBasementAtPosition;
  
    return [nextFloor, enteredBasementAtPosition];
  }, [0, undefined]);

console.log(endedOnFloor, enteredBasementAtPosition);

2.js

function calculatePaperArea (dimensions) {
  let [length, width, height] = dimensions;
  let sides = [2*length*width, 2*width*height, 2*height*length];
  return sides.reduce((total, side) => total + side) + (Math.min(...sides) / 2)
}

function calculateRibbonLength (dimensions) {
  let [length, width, height] = dimensions;
  return Math.min(2*(length+width),2*(width+height), 2*(height+length)) + length*width*height;
}

let input = fetch('https://gist.githubusercontent.com/soutar/e1f6fda416525a61bf54/raw/3bbd99a7e26feb85c5637c994330d12dc32f5f80/input.txt')
  .then(response => response.text())
  .then(text => {
    let boxStrings = text.split('\n');
    let boxes = boxStrings.map(dimensions => dimensions.split('x').map(char => parseInt(char)));
    
    let totalPaperArea = boxes.map(calculatePaperArea).reduce((total, item) => total + item);
    let totalRibbonLength = boxes.map(calculateRibbonLength).reduce((total, item) => total + item);
      
    console.log(totalPaperArea, totalRibbonLength);
  });
  

3.js

const directions = {
  "^": ([x, y]) => [x, y+1],
  ">": ([x, y]) => [x+1, y],
  "v": ([x, y]) => [x, y-1],
  "<": ([x, y]) => [x-1, y]
}

function processInstructions (instructions) {
  return instructions.reduce((history, instruction) => {
    let position = history[history.length - 1];
    let next = directions[instruction](position);
    return [...history, next];
  }, [[0, 0]]);
}

let input = fetch('https://gist.githubusercontent.com/soutar/32d089fec2df4592123a/raw/fbab1e1e3a45482e8bf00479eeb250c0b0f04ba6/input.txt')
  .then(response => response.text())
  .then(text => {
    let instructions = text.split('');
    let santas = 2;
    
    let paths = [...Array(santas)]
      .map((_, santa) =>
        instructions.filter((_, index) => index % santas === santa))
      .map(processInstructions);
      
    let houses = paths
      .reduce((combined, current) => [...combined, ...current])
      .filter(([x1, y1], index, path) =>
        path.findIndex(([x2, y2]) => x1 === x2 && y1 === y2) === index)
      .length;
    
    console.log(houses);
  });

4.js

import md5 from 'md5';

function findHashMatchingPattern (pattern = /.+/, secretKey = '', attempt = 1) {
  let hash = md5(`${secretKey}${attempt}`);
  return (pattern.exec(hash))
    ? [hash, attempt]
    : findHashMatchingPattern(pattern, secretKey, attempt+1);
}

let [hash, attempt] = findHashMatchingPattern(/^000000/, 'iwrupvqb');

5.js

import fetch from 'node-fetch';

// part 1
// const niceCriteria = [
//     string => string.split('').filter(character => ['a', 'e', 'i', 'o', 'u'].indexOf(character) > -1).length >= 3,
//     string => /(.)\1+/.exec(string),
//     string => ['ab', 'cd', 'pq', 'xy'].filter(substring => string.indexOf(substring) > -1).length === 0
// ];

// part 2
const niceCriteria = [
  string => /(..).*\1/.exec(string),
  string => /(.).\1/.exec(string)
]

function isNice (string) {
  return niceCriteria.filter(test => test(string)).length === niceCriteria.length
}

fetch('http://gist.githubusercontent.com/soutar/ba2b749385d6c99ce2c4/raw/c96bf95d2c7779596d7020528d6f712f0c531638/input.txt')
  .then(response => response.text())
  .then(response => {
    let strings = response.split('\n');
    let niceStrings = strings.filter(isNice);

    console.log(niceStrings.length);
  });

6.js

import fetch from 'node-fetch';

function parseInstruction (instruction, actions) {
  let [_, action, startx, starty, endx, endy] = instruction.match(instructionPattern);

  return {
    action: actions[action],
    start: [startx, starty],
    end: [endx, endy]
  }
}

function applyModification (grid, modification) {
  let { action, start, end } = modification;
  let [startx, starty] = start;
  let [endx, endy] = end;

  for (var x = parseInt(startx, 10); x <= endx; x++) {
    for (var y = parseInt(starty, 10); y <= endy; y++) {
      grid[x][y] = action(grid[x][y]);
    }
  }

  return grid;
}

const instructionPattern = /^([^0-9]+)\s([0-9]{1,3}),([0-9]{1,3}) through ([0-9]{1,3}),([0-9]{1,3})$/;
const height = 1000;
const width = 1000;

// part 1
// const LIGHT_OFF = false;
// const LIGHT_ON = true;
//
// const actions = {
//     'turn off': () => LIGHT_OFF,
//     'turn on': () => LIGHT_ON,
//     'toggle': (value) => !value
// }

// part 2
const LIGHT_OFF = 0;
const LIGHT_ON = 1;

const actions = {
    'turn off': (value) => Math.max(value - 1, LIGHT_OFF),
    'turn on': (value) => value + 1,
    'toggle': (value) => value + 2
}

const grid = [...Array(width)].map(column => [...Array(height)].map(node => LIGHT_OFF));

fetch('http://gist.githubusercontent.com/soutar/4fadd8451585cc6e03ab/raw/49ee684dd6cd825fabf6d2c1b0cf76248b71699d/input.txt')
  .then(response => response.text())
  .then(response => {

    let instructions = response.split('\n');
    let newGrid = instructions
      .map(instruction => parseInstruction(instruction, actions))
      .reduce(applyModification, grid);

    // // part 1
    // let onLights = newGrid.reduce(
    //   (on, column) => on + column.filter(node => node).length,
    //   0
    // );
    //
    // console.log(onLights);

    // part 2
    let totalLuminosity = newGrid.reduce(
      (luminosity, column) => luminosity + column.reduce(
        (luminosity, node) => luminosity + node, 0
      ), 0
    );

    console.log(totalLuminosity);
  });

7.js

import fetch from 'node-fetch';

const OPERATIONS = {
    'AND': (x, y) => x & y,
    'OR': (x, y) => x | y,
    'NOT': (value) => ~ value,
    'LSHIFT': (x, y) => x << y,
    'RSHIFT': (x, y) => x >> y
}

function parseInput (input) {
  let components = input.split(' ');
  let first;
  let operator;
  let second;

  switch (components.length) {
    case 1:
      return { components: [components] }
    break;
    case 2:
      [operator, first] = components;
      return { components: [first], operation: OPERATIONS[operator] };
    break;
    case 3:
      [first, operator, second] = components;
      return { components: [first, second], operation: OPERATIONS[operator] };
    break;
  }
}

function parseCircuitDefinition (circuitDefinition) {
  return circuitDefinition.split('\n').reduce((circuit, wire) => {
    let [input, output] = wire.split('->').map(string => string.trim());

    circuit[output] = parseInput(input);
    return circuit;
  }, {});
}

function readSignal (circuit, wire, state = {}) {
  let input = circuit[wire];
  let { operation } = input;

  if (state[wire]) {
    return state[wire];
  }

  let components = input.components.map(component => {
    return (!isNaN(component))
      ? parseInt(component)
      : readSignal(circuit, component, state);
  });

  let result = (operation)
    ? operation(...components)
    : components[0];

  return state[wire] = wrap(result, 0, 65536);
}

function wrap (number, min, max) {
  let range = max - min;
  return ((number - min) % range < 0)
    ? number + range
    : number;
}

fetch('https://gist.githubusercontent.com/soutar/60af14354c560946f992/raw/ae38f4a978c2d46578820595e0c77c168934958c/input.txt')
  .then(response => response.text())
  .then(response => {
    let circuit = parseCircuitDefinition(response);
    let signal = readSignal(circuit, 'a');
    console.log(signal);
  });