--- title: '46. Permutations' description: Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order icon: dot topics: - { name: "Array", slug: "array" } - { name: "Backtracking", slug: "backtracking" } issue: "https://github.com/prdlk/leetcode/issues/151" companies: - { name: "Bloomberg", period: "Thirty Days", frequency: 69.8 } - { name: "Amazon", period: "Thirty Days", frequency: 48.9 } - { name: "Microsoft", period: "Three Months", frequency: 42.1 } - { name: "Google", period: "Three Months", frequency: 32.7 } - { name: "Infosys", period: "Six Months", frequency: 67.9 } - { name: "LinkedIn", period: "Six Months", frequency: 54.1 } - { name: "Meta", period: "Six Months", frequency: 43.4 } sidebar: label: 'Permutations' badge: 'Medium' --- ### 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. ## Solution ```py class Solution: def permute(self, nums: list[int]) -> list[list[int]]: result, path = [], [] used = [False] * len(nums) def backtrack(): if len(path) == len(nums): result.append(path[:]) return for i in range(len(nums)): if used[i]: continue used[i] = True path.append(nums[i]) backtrack() path.pop() used[i] = False backtrack() return result ```