Climbing Stairs

Problem

Count ways to climb n stairs when each step climbs one or two stairs.

Examples

Example 1

Input: 5

Output: 8

Example 2

Input: 1

Output: 1

Input and output use JSON-compatible values. For linked-list and tree questions, arrays represent the node structure as described above. Your code should implement solve(input).

Write your solutionImplement solve(input). Your draft is saved in this browser.

Compiler

How to solve Climbing Stairs

Count ways to climb n stairs when each step climbs one or two stairs. The last move came from one or two steps below. The reference implementation illustrates this approach; check the example and edge cases.

Time and space complexity

O(n) time and O(1) space.

Practise and improve

Choose JavaScript, TypeScript or Python, complete the starter code, then select Run Tests. Request a hint when you need guidance, or choose View solution and confirm if you would like to study the reference implementation.