euler/e019.py
Correl Roush cd6bea96ee Problem 019
git-svn-id: file:///srv/svn/euler@46 e5f4c3ec-3c0c-11df-b522-21efaa4426b5
2010-04-14 19:19:30 +00:00

30 lines
920 B
Python

class Day:
SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY = range(7)
def is_leap_year(year):
return (year % 100 > 0 and year % 4 == 0) or (year % 400 == 0)
year = 1900
# 1/1/1900 was a Monday
first_day = Day.MONDAY
total = 0
while year < 2000:
year = year + 1
# Count last year's days to advance the starting weekday
days = 366 if is_leap_year(year - 1) else 365
# List the number of days in each month for this year
months = [
31,
29 if is_leap_year(year) else 28,
31, 30, 31, 30, 31, 31, 30, 31, 30, 31
]
first_day = (first_day + days % 7) % 7
sundays = 0
for m in range(len(months)):
days = sum(months[:m])
first_sunday = (7 - ((first_day + days % 7) % 7)) % 7 + 1
if first_sunday == 1:
total = total + 1
print 'Total months beginning on Sunday from 1/1/1901 to 12/31/2000: {0}'.format(total)