# 746 Min Cost Climbing Stairs

You are given an integer array `cost` where `cost[i]` is the cost of `ith` 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`
 ``````1 2 3 4 5 6 `````` ``````class Solution: def minCostClimbingStairs(self, cost: List[int]) -> int: p1, p2 = cost[0], cost[1] for i in range(2, len(cost)): p1, p2 = p2, min(p1, p2) + cost[i] return min(p1, p2)``````