A unit fraction contains 1 in the numerator. The decimal representation of the unit fractions with denominators 2 to 10 are given:
1/2 = 0.5 1/3 = 0.(3) 1/4 = 0.25 1/5 = 0.2 1/6 = 0.1(6) 1/7 = 0.(142857) 1/8 = 0.125 1/9 = 0.(1) 1/10 = 0.1
Where 0.1(6) means 0.166666..., and has a 1-digit recurring cycle. It can be seen that 1/7 has a 6-digit recurring cycle.
Find the value of d < 1000 for which 1/d contains the longest recurring cycle in its decimal fraction part.
def func(k):
dict={}
result=''
left=1
while True:
item=left*10//k
left=left*10-item*k
s=str(item)+"_"+str(left)
tempValue=dict.get(s)
if tempValue==None:
dict[s]=len(result)
result+=str(item)
else:
break
return len(result)-tempValue
result=7
num=6
for i in range(2,1000):
temp=func(i)
if temp>num:
result,num=i,temp
print(result)原文：http://blog.csdn.net/zhangzhengyi03539/article/details/46535731