public class Solution {

public int findTargetSumWays(int[] nums, int S) {

return back(nums,S,0,0,0);

}

public int back(int[] nums,int S,int sum,int k,int count){

if(k==nums.length){

if(sum==S){

count++;

}

return count;

}

else{

int a=0;

int b=0;

a=back(nums,S,sum+nums[k],k+1,count);

b=back(nums,S,sum-nums[k],k+1,count);

return a+b;

}

```
}
```

}