class Solution { public int solution(int[] numbers, int target) { int answer = 0; answer = dfs(numbers, 0, 0, target); return answer; } int dfs(int[] numbers, int n, int sum, int target) { if(n==numbers.length) { if(sum == target) { return 1; } return 0; } return dfs(numbers, n+1, sum + numbers[n],target) + dfs(numbers, n+1, sum - numbers[n], target); } }