# tingleshao/eulerMKII

problem 70

1 parent 0741543 commit e11e356cf5caebba4d0892d5b91ab87262cde404 committed Mar 30, 2013
Showing with 41 additions and 0 deletions.
1. +41 −0 problem61to70/problem70.py
 @@ -0,0 +1,41 @@ +# problem 70 +# http://www.mathblog.dk/project-euler-70-investigate-values-of-n-for-which-%CF%86n-is-a-permutation-of-n/ + +phi_best = 1 +best = 1 +best_ratio = 100000000 + + +def is_prime(n): + for i in range(2,n): + if n % i == 0: + return False + return True + +limit = 10000000 +prime_lst = [] +for n in range(2000,5001): + if is_prime(n): + prime_lst.append(n) + +for i in prime_lst: + for j in prime_lst: + n = i * j + if n > limit: + break + phi = (i - 1) * (j-1) + ratio = float(n) / phi + n_sort = list(str(n)) + n_sort.sort() + phi_sort = list(str(phi)) + phi_sort.sort() + if phi_sort == n_sort and best_ratio > ratio: + best = n + phi_best = phi + best_ratio = ratio + + +print "best: "+ str(best) +print "phi_best: " + str(phi_best) +print "best_ratio: " + str(best_ratio) +