solution.java

import java.util.Collections;
import java.util.HashMap;

public class Turing {
	private static HashMap<Integer, Boolean> tape = new HashMap<>();
	private static String state = "a";
	private static int pos = 0;

	public static void main(String[] args) {
		for(int i = 0; i < 12172063; i++) {
			if(tape.get(pos) == null)  tape.put(pos, false);
			boolean value = tape.get(pos);
			switch(state) {
				case "a":
					if(value) {
						tape.put(pos, false);
						pos--;
						state = "c";
					} else {
						tape.put(pos, true);
						pos++;
						state = "b";
					}
					break;
				case "b":
					if(value) state = "d";
					else state = "a";
					tape.put(pos, true);
					pos--;
					break;
				case "c":
					if(value) {
						tape.put(pos, false);
						state = "c";
					} else {
						tape.put(pos, true);
						state = "d";
					}
					pos++;
					break;
				case "d":
					tape.put(pos, false);
					if(value) {
						pos++;
						state = "e";
					} else {
						pos--;
						state = "b";
					}
					break;
				case "e":
					tape.put(pos, true);
					if(value) {
						pos--;
						state = "f";
					} else {
						pos++;
						state = "c";
					}
					break;
				case "f":
					tape.put(pos, true);
					if(value) {
						pos++;
						state = "a";
					} else {
						pos--;
						state = "e";
					}
					break;
			}
		}
		System.out.print(Collections.frequency((tape.values()), true));
	}
}