全排列-力扣解题

给定一个没有重复数字的序列，返回其所有可能的全排列。

示例:

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

import copy
class Solution:
    def permute(self, nums: list) -> list:
        result = []
        visited = {}
        for num in nums:
            visited[num] = False
        self.dfs(nums, result, visited, [])

        return result

    def dfs(self, nums:list, result:list, visited:dict, lst:list) -> None:
        if len(lst) == len(nums):
            result.append(copy.deepcopy(lst))
            return

        for num in nums:
            if not visited[num]:
                lst.append(num)
                visited[num] = True
                self.dfs(nums, result, visited, lst)
                lst.pop()
                visited[num] = False