Anonymous

public class Test implements Serializable {	public static void main(String args[]) throws Exception {		int size = 30;		int a = 0;		int b = (1<<size+1)-1;										for (int i=0;i<size;i+=2) {			print(b, size);			b ^= (1<<i+2)^(1<<size-i-1);					if (i < size-1) {				a ^= (1<<i+1)^(1<<size-i);				print(a, size);			}		}	}		private static void print(int a, int size) {		for (int i=0;i<size;i++) {			System.out.print((a&(1<<size-i))==0?" ":"O");		}		System.out.println();	}	}