题目：输入某年某年某月某日，判断这一天是这一年的第几天？思路：以3月5日为例，应该先把前两个月的加起来，然后再加上5天即本年的第几天，特殊情况，闰年且输入月份大于3考虑多加一天：year = int(input('year:\n'))month = int(input('month:\n'))day = int(input('day:\n'))months = [0,31,59,90,120,151,181,212,243,273,304,334]if 0 <= month <= 12:#判断输入的月份 sum = months[month - 1]else: print('data error')sum += dayleap = 0if ________________________________:#判断是平年还是润年 leap = 1if (leap == 1) and (month > 2): sum += 1print ('it is the %dth day.' % sum)