139 - 78 子集

题目

给定一组不含重复元素的整数数组 nums，返回该数组所有可能的子集（幂集）。

说明：解集不能包含重复的子集。

示例:

输入: nums = [1,2,3] 输出: [ [3], [1], [2], [1,2,3], [1,3], [2,3], [1,2], [] ]

解答

class Solution:
    def subsets(self, nums: List[int]) -> List[List[int]]:
        res = []

        def helper(level, temp):
            res.append(temp)
            for i in range(level, len(nums)):
                helper(i+1, temp+[nums[i]])
        helper(0, [])
        return res

Runtime: 28 ms, faster than 99.44% of Python3 online submissions for Subsets.

Memory Usage: 12.8 MB, less than 100.00% of Python3 online submissions for Subsets.

var subsets = function(nums) {
  const ans = []
  const helper = function(level, temp) {
    ans.push(temp)
    for (let i = level; i < nums.length; i++) {
      const next = temp.slice()
      next.push(nums[i])
      helper(i + 1, next)
    }
  }
  helper(0, [])
  return ans
};

Runtime: 60 ms, faster than 68.85% of JavaScript online submissions for Subsets.

Memory Usage: 34.9 MB, less than 47.06% of JavaScript online submissions for Subsets.

func subsets(nums []int) [][]int {
    ans := make([][]int, 0)
    var helper func(int, []int)
    helper = func(level int, temp []int) {
        ans = append(ans, temp)
        for i := level; i < len(nums); i++ {
            next := make([]int, len(temp))
            copy(next, temp)
            next = append(next, nums[i])
            helper(i+1, next)
        }
    }
    helper(0, []int{})
    return ans
}

Runtime: 0 ms, faster than 100.00% of Go online submissions for Subsets.

Memory Usage: 6.8 MB, less than 50.00% of Go online submissions for Subsets.