how to get all proper subsets of a set in swift

main.swift
func subsets(_ nums: [Int]) -> [[Int]] {
    var res = [[Int]]()
    var temp = [Int]()
    helper(&res, &temp, nums.sorted(), 0)
    return res
}

func helper(_ res: inout [[Int]], _ temp: inout [Int], _ nums: [Int], _ start: Int) {
    if temp.count > 0 && temp.count < nums.count {
        res.append(temp)
    }
    for i in start..<nums.count {
        temp.append(nums[i])
        helper(&res, &temp, nums, i + 1)
        temp.removeLast()
    }
}
454 chars
18 lines

main.swift
func subsets(_ nums: [Int]) -> [[Int]] {
    var res = [[Int]]()
    let n = nums.count
    for i in 0..<1<<n {
        var temp = [Int]()
        for j in 0..<n {
            if i>>j & 1 == 1 {
                temp.append(nums[j])
            }
        }
        if temp.count > 0 && temp.count < n {
            res.append(temp)
        }
    }
    return res
}
364 chars
17 lines