速算机器人

/*
 * Problem statement: Given two numbers x = 1 and y = 0, apply a sequence of operations to calculate the final sum of x and y.
 * Operations:
 * 'A': x = 2 * x + y
 * 'B': y = 2 * y + x
 * The input is a string of operations (s) consisting of 'A' and 'B'.
 * Return the sum of x and y after applying the operations in the order they appear in the string.
 * This solution uses Java Streams.
 */
import java.util.stream.Stream;

public class SolutionStream {
    public int calculate(String s) {
        int[] xy = {1, 0};
        Stream.of(s.split("")).forEach(operation -> {
            if (operation.equals("A")) {
                xy[0] = 2 * xy[0] + xy[1];
            } else if (operation.equals("B")) {
                xy[1] = 2 * xy[1] + xy[0];
            }
        });
        return xy[0] + xy[1];
    }
}