746\. Min Cost Climbing Stairs

Easy

You are given an integer array `cost` where `cost[i]` is the cost of <code>i<sup>th</sup></code> step on a staircase. Once you pay the cost, you can either climb one or two steps.

You can either start from the step with index `0`, or the step with index `1`.

Return _the minimum cost to reach the top of the floor_.

**Example 1:**

**Input:** cost = [10,15,20]

**Output:** 15

**Explanation:** You will start at index 1. - Pay 15 and climb two steps to reach the top. The total cost is 15.

**Example 2:**

**Input:** cost = [1,100,1,1,1,100,1,1,100,1]

**Output:** 6

**Explanation:** You will start at index 0. 

- Pay 1 and climb two steps to reach index 2. 
- Pay 1 and climb two steps to reach index 4. 
- Pay 1 and climb two steps to reach index 6. 
- Pay 1 and climb one step to reach index 7. 
- Pay 1 and climb two steps to reach index 9. 
- Pay 1 and climb one step to reach the top. 
  The total cost is 6.

**Constraints:**

*   `2 <= cost.length <= 1000`
*   `0 <= cost[i] <= 999`