One-dimensional cellular automata: Difference between revisions

{{trans|C}}

In this version, <code>b</code> is replaced by a <code>backup</code> which is local to the <code>evolve</code> method, and the <code>evolve</code> method returns a boolean.

<lang java>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));

}

}</lang>