27: Climb stairs
Given a staircase with a number
of steps. Count how many distinct
ways can you climb the stairs. In one step, you can climb one
or two
steps
Example 1
Input: 1
Output: 1
Explanation: One way to go up the stairs
Example 2
Input: 2
Output: 2
Explanation: Two ways climb the stairs:
- Climbing by one step
- Climbing by two steps