要想做到python语言求因数方法,首先要明白其中的原理:
1、对由123456789这九个数字组成的9位数进行分解质因数。
2、123457698=2x3x3x7x13x23x29x113,所以他的最大值因数是113。
3、总共有362880种可能,从中找出最大值因数中最小的数字和最大值因数中最大的数。
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好了,下面来看看python语言求因数方法的实现源码:
#coding:utf-8
import math
def generator(count, s):
if count == 1:
for i in s:
yield i
else:
for i in s:
_ = set(s)
_.remove(i)
for _ in generator(count-1, _):
yield _ * 10 + i
primes = [2, 3]
def prime(idx):
if idx < len(primes):
return primes[idx]
new = primes[-1]+2
while True:
for i in primes:
if new % i == 0:
break
else:
primes.append(new)
break
new += 2
return prime(idx)
def probe(number, idx, value=0):
if value > number:
return value
p = prime(idx)
sqrt = math.sqrt(number)
while number % p != 0 and sqrt >= p:
idx += 1
p = prime(idx)
if sqrt < p:
return number
return probe(number/p, idx, max(p, value))
if __name__ == '__main__':
_min = 10000000000, 10000000000
_max = 0, 0
for number in generator(9, set(range(1, 10))):
maxfactor = probe(number, 0)
if maxfactor < _min[0]:
_min = maxfactor, [number]
elif maxfactor == _min[0]:
_min[1].append(number)
if maxfactor > _max[0]:
_max = maxfactor, [number]
elif maxfactor == _max[0]:
_max[1].append(number)
print _min
print _max