[leetCode][JS] 70. Climbing Stairs

Description

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

Solution

var climbStairs = function(n) {
	let steps = [1 ,1];
	for (let i = 2; i < n + 1; i++) {
		steps.push(steps[i - 1] + steps[i -2]);
	}
	return steps[n];
};