User:Aadenboy/O(n) CGoL

O(n) implementation of Conway's Game of Life. Worded off of my Lua implementation of such.

1. All currently alive cells are stored in a hashmap B, where the key is the position of the cell.
2. Create two new empty hashmaps, one hashmap H for the counting of dead cells and another N for the new state of the board.
3. Loop through all currently alive cells in hashmap B.
   1. For each cell C, loop through all eight of its neighbors. Keep a count A of how many alive neighbors it has.
   2. If the neighbor is alive, increment A by one.
   3. If the neighbor is dead (or has no associated value in the hashmap B), increment its associated key in hashmap H by one, or set it to one if it does not exist.
   4. If the value in hashmap H is set to three, set the associated key in hashmap N to be alive.
   5. If the value in hashmap H is set to four (after being three), remove the associated key in hashmap N.
   6. After looping through all neighbors, set cell C's associated key in hashmap N to be alive if count A is two or three.
4. Set hashmap B to hashmap N. Discard hashmap H.