[프로그래머스] 타겟넘버

import java.util.*;

class Solution {
    int answer = 0;
    public int solution(int[] numbers, int target) {
        ArrayList<Integer> temp = new ArrayList<Integer>();
        for(int i=0; i<numbers.length; i++){
            temp.add(numbers[i]);
        }
        dfs(temp,target,0,0);
        
        return answer;
    }
    public void dfs(ArrayList<Integer> v, int dest, int sum, int idx){
        if(idx>=v.size()){
            if(sum == dest){
                answer++;
            }
            return;
        }
        dfs(v,dest,sum+v.get(idx),idx+1);
         dfs(v,dest,sum-v.get(idx),idx+1);
        
    }
}