Numbers can be regarded as the product of their factors.
- For example,
8 = 2 x 2 x 2 = 2 x 4.
Given an integer n, return all possible combinations of its factors. You may return the answer in any order.
Note that the factors should be in the range [2, n - 1].
Example 1:
Input: n = 1 Output: []
Example 2:
Input: n = 12 Output: [[2,6],[3,4],[2,2,3]]
Example 3:
Input: n = 37 Output: []
Example 4:
Input: n = 32 Output: [[2,16],[4,8],[2,2,8],[2,4,4],[2,2,2,4],[2,2,2,2,2]]
Constraints:
1 <= n <= 108