current state = start state

while (more input) {

	current input = next input

	switch (current state) {
		case X:
			switch (current input) {
				case A:
					.....
				case B:
					.....
				case C:
					.....
			}

		case Y:
			switch (current input) {
				case A:
					.....
				case B:
					.....
				case C:
					.....
			}				

		case Z:
			switch (current input) {
				case A:
					.....
				case B:
					.....
				case C:
					.....
			}	

	}
}