## Description #

Difficulty: **简单**

Related Topics: Memoization, Math, Dynamic Programming

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?

**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
```

**Constraints:**

`1 <= n <= 45`

## Solution #

Language: **Go**

IOI