Function dfs

javascript/0078-subsets.js:13–21

(nums, level = 0, set = [], subset = [])

};

var dfs = (nums, level = 0, set = [], subset = []) => {
    subset.push(set.slice());

    for (let i = level; i < nums.length; i++) {
        backTrack(nums, i, set, subset);
    }

    return subset;
};

const backTrack = (nums, i, set, subset) => {
    set.push(nums[i]);