https://projecteuler.net/problem=19
よく考えると、月の日数は2月を除けば簡単に求められますね。
fn is_leap_year(y: Int) -> Bool:
return y % 4 == 0 and (y % 100 != 0 or y % 400 == 0)
fn mdays(y: Int, m: Int) -> Int:
if m == 2:
return 29 if is_leap_year(y) else 28
else:
return 30 + m * 9 // 8 % 2
fn f() -> Int:
var counter = 0
var w = 1
for y in range(1900, 2001):
for m in range(1, 13):
if y >= 1901 and w == 0:
counter += 1
w = (w + mdays(y, m)) % 7
return counter
fn main():
print(f())
