숫자는 이미 정해져있으므로 (+)와 (-)만 생각해주면 된다!
class Solution {
int tar;
int[] number;
int answer = 0;
public void recur(int num, int index, char plusminus){
if(index == number.length){
if(tar == num){
answer++;
}
return;
}
if(plusminus == '+'){
num += number[index];
}
else{
num -= number[index];
}
recur(num, index+1, '+');
recur(num, index+1, '-');
}
public int solution(int[] numbers, int target) {
tar = target;
number =numbers;
recur(0, 0, '+');
recur(0, 0, '-');
return answer / 2;
}
}