直接模拟就能搞定, 两个主要函数

int getStepAB(int A, int B, int C)
{
	int steps = 0, b = 0;
	bool come[N + 2] = {0};

	while (true) {
		if (A + b <= B) {
			execCommand(FILL1);execCommand(POUR12);
			steps += 2;
			b += A;
			if (b == C)
				break;
			if (come[b])
				return -1;
			come[b] = true;
		} else {
			execCommand(FILL1);execCommand(POUR12);
			steps += 2;
			int a = A - (B - b);
			if (C == a)
				break;
			execCommand(DROP2);execCommand(POUR12);
			steps += 2;
			b = a;
			if (come[b])
				return -1;
			come[b] = true;
		}
	}
	return steps;
}


int getStepBA(int A, int B, int C)
{
	int steps = 0, b = 0;
	bool come[N + 2] = {0};
	if (b == 0) {
		execCommand(FILL2);
		b = B;
		steps = 1;
	} else if (b == C) {
		return 1;
	}

	while (true) {
		if (A <= b) {
			execCommand(POUR21);
			steps += 1;
			b -= A;
			if (b == C)
				break;
			execCommand(DROP1);
			steps += 1;
			if (come[b])
				return -1;
			come[b] = true;
		} else {
			execCommand(POUR21);
			int a = b;
			b = 0;
			execCommand(FILL2);
			execCommand(POUR21);
			b = B - (A - a);
			steps += 3;
			if (b == C)
				break;
			execCommand(DROP1);
			steps += 1;
			if (come[b])
				return -1;
			come[b] = true;
		}
	}

	return steps;
}