CellularAutonoma.java

public class CellularAutonoma {
	public static void main(String[] args) {
		boolean[] cells = parseCells(args[0]);
		for (int age = 0; age < 25; age++) {
			printCells(cells);
			cells = tickCells(cells);
		}
		printCells(cells);
	}
	
	private static boolean[] parseCells(String state) {
		boolean[] cells = new boolean[state.length()];
		for (int index = 0; index < cells.length; index++) {
			cells[index] = state.charAt(index) == '1';
		}
		return cells;
	}
	
	private static boolean[] tickCells(boolean[] cells) {
		boolean[] nextState = new boolean[cells.length];
		for (int index = 0; index < cells.length; index++) {
			nextState[index] = getState(cells, index);
		}
		return nextState;
	}
	
	private static boolean getState(boolean[] cells, int index) {
		if (cells.length < 2) {
			return false;
		}
		if (index == 0) {
			return cells[1];
		}
		if (index == cells.length - 1) {
			return cells[cells.length - 2];
		}
		return cells[index - 1] != cells[index + 1];
	}
	
	private static void printCells(boolean[] cells) {
		for (boolean bool : cells) {
			System.out.print(bool ? 'x' : ' ');
		}
		System.out.println();
	}
}