83. Climbing Stairs

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Input: [2]

Output: 2

Explanation: There are two ways to climb to the top. 1. 1 step + 1 step 2. 2 steps

Input: n = [3]

Output: 3

Explanation: There are three ways to climb to the top. 1. 1 step + 1 step + 1 step 2. 2 steps + 1 step 3. 1 step + 2 steps

Note: This is equivalent to computing Fibonacci numbers; you can solve with O(n) time and O(1) space.

Time Complexity

O(n)

Space Complexity

O(1)