Problem26.py

# Code by @AmirMotefaker

# projecteuler.net
# https://projecteuler.net/problem=26

# Reciprocal cycles
# Problem 26

# 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.

import time
start_time = time.time()   #Time at the start of program execution

num = longest = 1
for n in range(3, 1000, 2):
    if n % 5 == 0:
        continue

    p = 1
    while (10 ** p) % n != 1:
        p += 1

    if p > longest:
        num, longest = n, p

print (num)

end_time = time.time()   #Time at the end of execution
print ("Time of program execution:", (end_time - start_time))   # Time of program execution



### Answer:  983