Solution to Advent of Code 3

aocd3.js

function sum (x) {
  var sum = 0;

  while(x > 0) {
     sum = sum + x;
     x--;
  }
  
  return sum;
}

function getNumberBlock (number) {
  return Math.ceil((Math.sqrt(number) - 1) / 2);
}

function getNumberPosition (number) {
  if (number === 0) {
    return {
      x: 0,
      y: 0
    };
  }

  var blockIndex = getNumberBlock(number);
  var blockLength = blockIndex * 2;
  var initialBlockNumber = 8 * sum(blockIndex);
  var x = -1 * blockIndex;
  var y = -1 * blockIndex;
  
  // we need to run this in 0-index mode
  number = number - 1;
    
  if (number >= (initialBlockNumber - blockLength) && number < initialBlockNumber) {
    x = x + (initialBlockNumber - number);
  }
  
  initialBlockNumber = initialBlockNumber - blockLength;
    
  if (number >= (initialBlockNumber - blockLength) && number < initialBlockNumber) {
    y = y + (initialBlockNumber - number);
  }
  
  initialBlockNumber = initialBlockNumber - blockLength;
    
  if (number >= (initialBlockNumber - blockLength) && number < initialBlockNumber) {
    x = x + (initialBlockNumber - number);
    y = Math.abs(y)
  }
  
  initialBlockNumber = initialBlockNumber - blockLength;
    
  if (number >= (initialBlockNumber - blockLength) && number < initialBlockNumber) {
    y = y + (initialBlockNumber - number);
    x = Math.abs(x);
  }
  
  return {
    x: x,
    y: y
  };
}

function getDistance (number) {
  var coordinates = getNumberPosition(number);

  return Math.abs(coordinates.x) + Math.abs(coordinates.y);
}

console.log(getDistance(289326));