# In a country popular for train travel, you have planned some train travelling one year in advance.  The days of the
#  year that you will travel is given as an array days.  Each day is an integer from 1 to 365.
#
# Train tickets are sold in 3 different ways:
#
# a 1-day pass is sold for costs[0] dollars;
# a 7-day pass is sold for costs[1] dollars;
# a 30-day pass is sold for costs[2] dollars.
# The passes allow that many days of consecutive travel.  For example, if we get a 7-day pass on day 2, then we can
# travel for 7 days: day 2, 3, 4, 5, 6, 7, and 8.
#
# Return the minimum number of dollars you need to travel every day in the given list of days.
#
#
#
# Example 1:
#
# Input: days = [1,4,6,7,8,20], costs = [2,7,15]
# Output: 11
# Explanation:
# For example, here is one way to buy passes that lets you travel your travel plan:
# On day 1, you bought a 1-day pass for costs[0] = $2, which covered day 1.
# On day 3, you bought a 7-day pass for costs[1] = $7, which covered days 3, 4, ..., 9.
# On day 20, you bought a 1-day pass for costs[0] = $2, which covered day 20.
# In total you spent $11 and covered all the days of your travel.
# Example 2:
#
# Input: days = [1,2,3,4,5,6,7,8,9,10,30,31], costs = [2,7,15]
# Output: 17
# Explanation:
# For example, here is one way to buy passes that lets you travel your travel plan:
# On day 1, you bought a 30-day pass for costs[2] = $15 which covered days 1, 2, ..., 30.
# On day 31, you bought a 1-day pass for costs[0] = $2 which covered day 31.
# In total you spent $17 and covered all the days of your travel.
#
#
# Note:
#
# 1 <= days.length <= 365
# 1 <= days[i] <= 365
# days is in strictly increasing order.
# costs.length == 3
# 1 <= costs[i] <= 1000


class Solution(object):
    def mincostTickets(self, days, costs):
        """
        :type days: List[int]
        :type costs: List[int]
        :rtype: int
        """
        N = days[-1]
        minCost = [0] * (N + 1)

        for i in xrange(1, N + 1):
            # I didn't think out this case how to handle
            if i not in days:
                minCost[i] = minCost[i - 1]
            else:
                minCost[i] = min(minCost[i - 1] + costs[0], minCost[max(i - 7, 0)] + costs[1],
                                 minCost[max(i - 30, 0)] + costs[2])

        return minCost[N]


if __name__ == '__main__':
    print Solution().mincostTickets([1, 4, 6, 7, 8, 20], [2, 7, 15])
    print Solution().mincostTickets([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 30, 31], [2, 7, 15])
