Source code in the java programming language

public class Life{
	public static void main(String[] args) throws Exception{
		String start= "_###_##_#_#_#_#__#__";
		int numGens = 10;
		for(int i= 0; i < numGens; i++){
			System.out.println("Generation " + i + ": " + start);
			start= life(start);
		}
	}

	public static String life(String lastGen){
		String newGen= "";
		for(int i= 0; i < lastGen.length(); i++){
			int neighbors= 0;
			if (i == 0){//left edge
				neighbors= lastGen.charAt(1) == '#' ? 1 : 0;
			} else if (i == lastGen.length() - 1){//right edge
				neighbors= lastGen.charAt(i - 1) == '#' ? 1 : 0;
			} else{//middle
				neighbors= getNeighbors(lastGen.substring(i - 1, i + 2));
			}

			if (neighbors == 0){//dies or stays dead with no neighbors
				newGen+= "_";
			}
			if (neighbors == 1){//stays with one neighbor
				newGen+= lastGen.charAt(i);
			}
			if (neighbors == 2){//flips with two neighbors
				newGen+= lastGen.charAt(i) == '#' ? "_" : "#";
			}
		}
		return newGen;
	}

	public static int getNeighbors(String group){
		int ans= 0;
		if (group.charAt(0) == '#') ans++;
		if (group.charAt(2) == '#') ans++;
		return ans;
	}
}


public class Life{
	private static char[] trans = "___#_##_".toCharArray();

	private static int v(StringBuilder cell, int i){
		return (cell.charAt(i) != '_') ? 1 : 0;
	}

	public static boolean evolve(StringBuilder cell){
		boolean diff = false;
		StringBuilder backup = new StringBuilder(cell.toString());

		for(int i = 1; i < cell.length() - 3; i++){
			/* use left, self, right as binary number bits for table index */
			backup.setCharAt(i, trans[v(cell, i - 1) * 4 + v(cell, i) * 2
			      					+ v(cell, i + 1)]);
			diff = diff || (backup.charAt(i) != cell.charAt(i));
		}

		cell.delete(0, cell.length());//clear the buffer
		cell.append(backup);//replace it with the new generation
		return diff;
	}

	public static void main(String[] args){
		StringBuilder  c = new StringBuilder("_###_##_#_#_#_#__#__\n");

		do{
			System.out.printf(c.substring(1));
		}while(evolve(c));
	}
}