70. Climbing Stairs

[Jian-Min-Huang]

You are climbing a stair case. It takes n steps to reach to the top.

Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?

Note: Given n will be a positive integer.

Example 1:

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

Example 2:

Input: 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

[Jian-Min-Huang]

89

f(n) = f(n-2) + f(n-1)

f(1) -> f(2) -> ... -> f(10)

[Jian-Min-Huang]

https://github.com/Jian-Min-Huang/leetcode-practice/blob/master/src/com/leetcode/easy/ClimblingStairs.java