def main(limit): # trick: to maximize phi(n) need n to be a product of two primes, as it can't be prime itself minn, minphi = 1, -1 for p1 in primes.gen(): if p1 * 3 >= limit: break p2lim = min(p1, limit / p1) for p2 in takewhile(lambda p: p < p2lim, primes.gen()): n = p1 * p2 phi = (p1 - 1) * (p2 - 1) if n * minphi < minn * phi and digitCountMap(n) == digitCountMap(phi): minn, minphi = n, phi return minn
def main(limit):
# trick: to maximize phi(n) need n to be a product of two primes, as it can't be prime itself
minn, minphi = 1, -1
for p1 in primes.gen():
if p1 * 3 >= limit:
break
p2lim = min(p1, limit / p1)
for p2 in takewhile(lambda p: p < p2lim, primes.gen()):
n = p1 * p2
phi = (p1 - 1) * (p2 - 1)
if n * minphi < minn * phi and digitCountMap(n) == digitCountMap(
phi):
minn, minphi = n, phi
return minn
def group(nums): record = dict() for n in nums: record.setdefault(digitCountMap(n), []).append(n) return record.values()
