title: Better A* Search Heuristic in a 2-d grid world
body: <p>I am still new with the idea of A* Search. I understand some of the Heuristic that A* Search have such as Straight-Line Distance (Euclidean Distance), Manhattan Distance and Misplaced Tiles (for 8 puzzle game).</p>
  
  <p>For the 2-d grid world,
  Which is better admissible heuristic than Straight-Line Distance. I have my mind on Manhattan Distance. Any other suggestion?</p>