climbing-stairs

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70. Climbing Stairs (Easy)

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

Related Topics

[Math] [Dynamic Programming] [Memoization]

Similar Questions

1. Min Cost Climbing Stairs (Easy)
2. Fibonacci Number (Easy)
3. N-th Tribonacci Number (Easy)

Hints

Hint 1

To reach nth step, what could have been your previous steps? (Think about the step sizes)