## Challenge Statement

- You are climbing a staircase. It takes
`n`

steps to reach the top. - Each time you can either climb
`1`

or`2`

steps. In how many distinct ways can you climb to the top? - This challenge corresponds to LeetCode #70.

### Constraints

`1 <= n <= 45`

**Example 1:**

```
Input: n = 2
Output: 2
Explanation: There are two ways to climb to the top.
1. 1 step + 1 step
2. 2 steps
```

**Example 2:**

```
Input: n = 3
Output: 3
Explanation: There are three ways to climb to the top.
1. 1 step + 1 step + 1 step
2. 1 step + 2 steps
3. 2 steps + 1 step
```

## Solution

Below is my solution and some test cases. This solution has a **linear time complexity O(n) and a linear space complexity O(n)**, where n is the number of steps*.*