### Climbing Stairs ===================== ### Problem Statement ------------------- You are climbing a staircase that has `n` stairs. At each step, you can either climb 1 or 2 stairs. Determine the total number of distinct ways to climb to the top of the staircase. ### Rules and Constraints ------------------------- * The staircase has `n` stairs. * At each step, you can either climb 1 or 2 stairs. * You must reach the top of the staircase. * You are not allowed to climb more than 2 stairs at a time. ### Time and Space Complexity ------------------------------ The algorithm should have a time complexity of O(n) and a space complexity of O(n) (due to the recursion stack). Alternatively, an iterative solution with a space complexity of O(1) is also acceptable. ### Notes ------- No additional notes or assumptions are provided. You should use the given constraints and rules to determine the final answer. ### Example **Input:** {"input_data":[1,2,3]} **Output:** [1,2,3]