LeetCode-in-All

46. Permutations

Medium

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:

Solution

defmodule Solution do
  @spec permute(nums :: [integer]) :: [[integer]]
  def permute([]),   do: [[]] 
  def permute(nums), do: for h <- nums, t <- permute(nums -- [h]), do: [h | t]
end