Description

Given a list of numbers, return all possible permutations.

Notice

You can assume that there is no duplicate numbers in the list.

Example

For nums =[1,2,3], the permutations are:

[
  [1,2,3],
  [1,3,2],
  [2,1,3],
  [2,3,1],
  [3,1,2],
  [3,2,1]
]

Solution

因为数组中没有重复的数组，所以只要判断一下list里面有没有nums[i]就行了

For nums = [1,2,3], the permutations are:

[
  [1,2,3],
  [1,3,2],
  [2,1,3],
  [2,3,1],
  [3,1,2],
  [3,2,1]
]