day-of-the-year.py

# Time:  O(1)
# Space: O(1)

class Solution(object):
    def __init__(self):
        def dayOfMonth(M):
            return (28 if (M == 2) else 31-(M-1)%7%2)

        self.__lookup = [0]*12
        for M in xrange(1, len(self.__lookup)):
            self.__lookup[M] += self.__lookup[M-1]+dayOfMonth(M)
            
    def dayOfYear(self, date):
        """
        :type date: str
        :rtype: int
        """
        Y, M, D = map(int, date.split("-"))
        leap = 1 if M > 2 and (((Y % 4 == 0) and (Y % 100 != 0)) or (Y % 400 == 0)) else 0
        return self.__lookup[M-1]+D+leap


# Time:  O(1)
# Space: O(1)
class Solution2(object):
    def dayOfYear(self, date):
        """
        :type date: str
        :rtype: int
        """
        def numberOfDays(Y, M):
            leap = 1 if ((Y % 4 == 0) and (Y % 100 != 0)) or (Y % 400 == 0) else 0
            return (28+leap if (M == 2) else 31-(M-1)%7%2)

        Y, M, result = map(int, date.split("-"))
        for i in xrange(1, M):
            result += numberOfDays(Y, i)
        return result