46 Permutations

Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order.

Example 1:

Input: nums = [1,2,3]
Output: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]

Example 2:

Input: nums = [0,1]
Output: [[0,1],[1,0]]

Example 3:

Input: nums = [1]
Output: [[1]]

Constraints:

• 1 <= nums.length <= 6
• -10 <= nums[i] <= 10
• All the integers of nums are unique.

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class Solution:

    def permute(self, nums: List[int]) -> List[List[int]]:
        if not nums:
            return [[]]
        res = []
        for i, num in enumerate(nums):
            perm = self.permute(nums[:i] + nums[i+1:])
            for p in perm:
                res.append([num] + p)
        return res