题目描述

代码实现

import UIKit

func subsets(_ nums: [Int]) -> [[Int]] {
    
    var results = [[Int]]()
    
    for num in nums {
        
        for result in results {
            results.append(result + [num])
        }
        
        results.append([num])
    }
    results.append([])
    return results
}

var nums = [1,2,3]

subsets(nums)

Q.E.D.