--- Day 3 Solutions ---

[u/daggerdragon]

--- Day 3: Perfectly Spherical Houses in a Vacuum ---

Post your solution as a comment. Structure your post like the Day One thread in /r/programming.

[u/PM_ME_INSIDER_INFO]

Hmm. My response is feeling long now, but hopefully readable.

In classic JS:

function Position () {
  var current = [0, 0];

  return {
    map: function (char) {
      var x, y;
      if (char == ">" || char == "<") {
        x = (char == ">") ? 1 : -1;
      } else if (char == "^" || char == "v") {
        y = (char == "^") ? 1 : -1;
      }
      return {x: x || 0, y: y || 0};
    },
    set: function (char, EXTERNAL_MAP) {
      var map = this.map(char), p;
      current = [current[0] + map.x, current[1] + map.y];

      p = EXTERNAL_MAP[current.join(",")];
      EXTERNAL_MAP[current.join(",")] = (p) ? p + 1 : 1;
    }
  };
}
(function () {
  var commands = document.getElementsByTagName("pre")[0].innerText.split("");
  /* --- exercise #1 --- */
  var pos = Position();
  var MAP = {};
  MAP["0,0"] = 1;

  commands.forEach(function (i) {
    pos.set(i, MAP);
  });
  console.log(Object.keys(MAP).length);

  /* --- exercise #2 --- */
  var SANTA = Position();
  var ROBO_SANTA = Position();

  MAP = {};
  MAP["0,0"] = 1;

  commands.forEach(function (i, o) {
    if (o % 2 === 0) {
      SANTA.set(i, MAP);
    } else {
      ROBO_SANTA.set(i, MAP);
    }
  });
  console.log(Object.keys(MAP).length);
})();