Created
October 27, 2013 06:02
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This code finds the primitive roots of a relatively small number. It is not optimized for very large numbers.
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from fractions import gcd | |
import copy | |
def get_relative_primes(number): | |
# will hold all numbers that are relatively prime to number | |
rel_primes = set() | |
# Dictionary: key is primitive root | |
# value is the set of powers mod number | |
prim_root_dict = {} | |
# Dictionary: key is a relative prime to number | |
# value is the set of powers mod number | |
all_powers = {} | |
# will hold the number or relative primes: phi(n) | |
phi = 0 | |
# get relative primes to the number | |
for i in range(1, number): | |
if gcd(i, number) is 1: | |
rel_primes.add(i) | |
phi = phi + 1 | |
# iterate through all relative primes to find primitive | |
# roots | |
for i in rel_primes: | |
temp_relprimes = copy.deepcopy(rel_primes) | |
prim_set = set() | |
# get all rel_primes [0..phi(n)]th power mod number: i^[0..phi(i)] mod number | |
for n in range(phi): | |
rp = 1; | |
# get to the nth power the efficient way | |
for p in range(n + 1): | |
rp = (rp * i) % number | |
''' | |
determine if rp is in the set of relative primes.if so, | |
add n to the primitive set of this relative prime and | |
remove it from the temporary set of relative primes. | |
''' | |
if rp in temp_relprimes: | |
prim_set.add(rp) | |
temp_relprimes.remove(rp) | |
all_powers[i] = prim_set | |
if len(temp_relprimes) is 0: | |
prim_root_dict[i] = prim_set | |
print("all numbers relatively prime to " + str(number) + ": ") | |
print("\t" + str(list(rel_primes))) | |
print("phi(" + str(number) + "): " + str(phi)) | |
print("="*100) | |
print("bd"*50) | |
print("pq"*50) | |
print("="*100) | |
print("all powers Z(" + str(number) + "):") | |
for i in all_powers: | |
print(str(i) + ":\t" + str(list(all_powers[i]))) | |
print("="*100) | |
print("bd"*50) | |
print("pq"*50) | |
print("="*100) | |
count = len(prim_root_dict) | |
print("all primitive roots:") | |
if count is not 0: | |
print("Size:\t" + str(count)) | |
print("PR:\t" + str(prim_root_dict.keys()) + "\n" + "-"*10) | |
for i in prim_root_dict: | |
print(str(i) + ":\t" + str(list(prim_root_dict[i]))) | |
else: | |
print("\tNo primitive root") | |
get_relative_primes(25) | |
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