240103 타겟 넘버

public int solution(int[] numbers, int target) {
	return dfs(numbers, 0, target, 0, 0);
}

public int dfs(int[] numbers, int depth, int target, int sum, int answer) {
	if (depth == numbers.length) {
		return (target == sum) ? answer + 1 : answer;
	} else {
		int result1 = dfs(numbers, depth + 1, target, sum + numbers[depth], answer);
		int result2 = dfs(numbers, depth + 1, target, sum - numbers[depth], answer);
		return result1 + result2;
	}
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/43165