clean up

First_edition_2014/other_resources/Project-Euler/026-reciprocal-cycles.py

@@ -0,0 +1,40 @@
+#!/usr/bin/python3
+# mari wahl @2014
+# marina.w4hl at gmail
+
+
+'''
+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.
+
+Answer: 983
+'''
+
+
+def recurring_cycle(n, d):
+    for dd in range(1, d):
+        if 1 == 10**dd % d:
+            return dd
+    return 0
+
+def main():
+  n = 1
+  limit = 1000
+  longest = max(recurring_cycle(n, i) for i in range(2, limit+1))
+  print [i for i in range(2, limit+1) if recurring_cycle(n, i) == longest][0]
+
+if __name__ == '__main__':
+    main()
+