README_EN.md

78. Subsets

中文文档

Description

Given a set of distinct integers, nums, return all possible subsets (the power set).

Note: The solution set must not contain duplicate subsets.

Example:

Input: nums = [1,2,3]

Output:

[

  [3],

  [1],

  [2],

  [1,2,3],

  [1,3],

  [2,3],

  [1,2],

  []

]

Solutions

Python3

class Solution:
    def subsets(self, nums: List[int]) -> List[List[int]]:
        def dfs(nums, i, res, path):
            res.append(copy.deepcopy(path))
            while i < len(nums):
                path.append(nums[i])
                dfs(nums, i + 1, res, path)
                path.pop()
                i += 1
        res, path = [], []
        dfs(nums, 0, res, path)
        return res

Java

class Solution {
    public List<List<Integer>> subsets(int[] nums) {
        List<Integer> path = new ArrayList<>();
        List<List<Integer>> res = new ArrayList<>();
        dfs(nums, 0, res, path);
        return res;
    }

    private void dfs(int[] nums, int i, List<List<Integer>> res, List<Integer> path) {
        res.add(new ArrayList<>(path));
        while (i < nums.length) {
            path.add(nums[i]);
            dfs(nums, i + 1, res, path);
            path.remove(path.size() - 1);
            ++i;
        }
    }
}

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