프로그래머스 - 타겟넘버

#include <string>
#include <vector>

using namespace std;

int answer = 0;

void recursive(vector<int> numbers, int target, int sum,int index){
    
    if(index == numbers.size())
    {
        if(sum==target) answer++;   
        
        return;
    }
    recursive (numbers, target, sum+numbers[index], index+1);
    recursive (numbers, target, sum-numbers[index], index+1);
       
}

int solution(vector<int> numbers, int target) {
    
    recursive(numbers, target , 0,0);
    
    
    
    return answer;
}