1863. Sum of All Subset XOR Totals.cpp

난이도가 높아지니까, dp알고리즘 활용 문제가 자꾸 나온다 😕

//thanks to https://www.youtube.com/watch?v=CJ9EicV9nWc&ab_channel=CODE_CROSING


class Solution {
public:

    int subsetXORSum(vector<int>& nums) {
        return helper(nums, 0,0);
    }

    int helper(vector<int>&nums,int level, int currentXOR){

        if(level == nums.size()) return currentXOR;

        int inc = helper(nums,level +1,currentXOR^nums[level]);
        int exc = helper(nums,level +1,currentXOR);

        return inc + exc;
    }
};