Lintcode 1054. Min Cost Climbing Stairs (Easy) (Python)

1054. Min Cost Climbing Stairs

Description:

On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed).

Once you pay the cost, you can either climb one or two steps. You need to find minimum cost to reach the top of the floor, and you can either start from the step with index 0, or the step with index 1.

Example
Example 1:

Input: cost = [10, 15, 20]
Output: 15
Explanation: Cheapest is start on cost[1], pay that cost and go to the top.
Example 2:

Input: cost = [1, 100, 1, 1, 1, 100, 1, 1, 100, 1]
Output: 6
Explanation: Cheapest is start on cost[0], and only step on 1s, skipping cost[3].

Code:

class Solution:
    """
    @param cost: an array
    @return: minimum cost to reach the top of the floor
    """
    def minCostClimbingStairs(self, cost):
        # Write your code here
        l = len(cost)
        if (l == 0):
            return 0
        if (l == 1):
            return cost[0]
        if (l == 2):
            return cost.min()
        sto = []
        sto.append(cost[0])
        sto.append(cost[1])
        for i in range(2, l):
            i1 = sto[i-1]
            i2 = sto[i-2]
            m = min(i1,i2)
            sto.append(m+cost[i])
        return min(sto[l-1], sto[l-2])