19 lines
495 B
Python
19 lines
495 B
Python
|
#!/usr/bin/env python3
|
||
|
|
|
||
|
|
from fractions import Fraction
|
||
|
|
|
||
|
|
def search(turns, wins=0, discs=2, cache={}):
|
||
|
|
if discs - 2 == turns:
|
||
|
|
return 2* wins > turns
|
||
|
|
if turns // 2 - wins > turns - discs + 1:
|
||
|
|
return 0
|
||
|
|
if (discs, wins) in cache:
|
||
|
|
return cache[(discs, wins)]
|
||
|
|
r = Fraction(1, discs) * search(turns, wins+1, discs+1)
|
||
|
|
r += Fraction(discs-1, discs) * search(turns, wins, discs+1)
|
||
|
|
cache[(discs, wins)] = r
|
||
|
|
return r
|
||
|
|
|
||
|
|
N = 15
|
||
|
|
print(int(search(N)**(-1)))
|