题目：给你一个日期，请你设计一个算法来判断它是对应一周中的哪一天。
输入为三个整数：day、month和year，分别表示日、月、年。
您返回的结果必须是这几个值中的一个{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}。
解法：求天数与1971年1月1日的差值，因为已知1971年1月1日为星期五
代码：
class Solution(object):def dayOfTheWeek(self, day, month, year):""":type day: int:type month: int:type year: int:rtype: str"""days=4+day"""1971年1月1日是星期五"""for i in range(1971,year):if i % 400 == 0 or (i % 100 != 0 and i % 4 == 0):days=days+366else:days=days+365days = days % 7d=["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]m1 = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]m2 = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]if year%400==0 or (year%100!=0 and year%4==0):for i in range(month-1):days=m2[i]+dayselse:for i in range(month-1):days=m1[i]+daysprint(d[days%7])return d[days%7]
