MediumBacktrackingAI interview only
Permutations
Asked atmetaamazongooglemicrosoftbloomberglinkedinapple
01 · Problem
Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order.
02 · Examples
Example 01
Input
nums = [1,2,3]
Output
[[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
All 6 permutations of [1,2,3] are listed.
Example 02
Input
nums = [0,1]
Output
[[0,1],[1,0]]
There are 2 permutations of a 2-element array.
Example 03
Input
nums = [1]
Output
[[1]]
A single element has exactly one permutation.
03 · Constraints
- 011 <= nums.length <= 6
- 02-10 <= nums[i] <= 10
- 03All the integers of nums are unique
04 · Optimal complexity
- Time
- O(n! * n)
- Space
- O(n!)
05 · Two ways to work on it
Practice it alone or rehearse it as an interview.
Practice Mode gives you an editor and test runs, nothing else. AI Interview Mode puts a voice interviewer on the other side, adds a clock, and ends with a scored summary of the round.