Grokking the Coding Interview: Patterns for Coding Questions

Solution: Factor Combinations

## Problem Statement

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**.


**Example 1**:  
```
Input: n = 8  
Output: [[2, 2, 2], [2, 4]]   
```    

**Example 2**:  
```
Input: n = 20  
Output: [[2, 2, 5], [2, 10], [4, 5]]  
```

**Constraints:**

- 2 <= n <= 10<sup>7</sup>

## Solution


We can use backtracking to find all the factors of a given number $n$.