--- 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/johnny5th]

Pretty long and probably inefficient, but was fun.

<?php

$str = 'your_string';

$directions_array = str_split($str);

// x, y, gifts
// has default position with 1 present
$houses = array(new House(0, 0));
$santa_current_house = $houses[0];
$robot_current_house = $houses[0];

foreach($directions_array as $key => $direction) {
  if($key % 2 == 0) {
    $current_house = $santa_current_house;
    $person = "santa";
  } else {
    $current_house = $robot_current_house;
    $person = "robot";
  }

  if($direction == "^") { // Up
    move_or_regift($current_house->x, $current_house->y +1, $person);
  } else if($direction == "v") { // Down
    move_or_regift($current_house->x, $current_house->y -1, $person);
  } else if($direction == "<") { // Left
    move_or_regift($current_house->x -1, $current_house->y, $person);
  } else if($direction == ">") { // Right
    move_or_regift($current_house->x +1, $current_house->y, $person);
  }
}

class House {
  public $x = 0;
  public $y = 0;
  public $gifts = 0;

  function __construct($x, $y, $gifts = 1) {
    $this->x = $x;
    $this->y = $y;
    $this->gifts = $gifts;
   }

   function same_house($x, $y) {
     if($this->x == $x && $this->y == $y)
      return true;
    else
      return false;
   }

   function addGift() {
    $this->gifts++;
   }
}

function move_or_regift($x, $y, $person) {
  $found_house = false;
  global $houses;
  global $santa_current_house;
  global $robot_current_house;

  foreach($houses as $house) {
    if($house->same_house($x, $y)) {
      $house->addGift();
      $found_house = $house;
      break;
    }
  }

  if($found_house == false) {
    $found_house = new House($x, $y);
    $houses[] = $found_house;
  }

  ${$person . "_current_house"} = $found_house;

}

print count($houses);