The challenge
Wilson primes satisfy the following condition. Let P represent a prime number.
Then ((P-1)! + 1) / (P * P) should give a whole number.
Your task is to create a function that returns true if the given number is a Wilson prime.
The solution in Python code
Option 1:
def am_i_wilson(n):
return n in (5, 13, 563)
Option 2:
def am_i_wilson(n):
if n < 2 or not all(n % i for i in xrange(2, n)):
return False
import math
return (math.factorial(n - 1) + 1) % (n ** 2) == 0
Option 3:
def am_i_wilson(n):
return n == 5 or n == 13 or n == 563
Test cases to validate our solution
test.assert_equals(am_i_wilson(0), False)
test.assert_equals(am_i_wilson(1), False)
test.assert_equals(am_i_wilson(5), True)
test.assert_equals(am_i_wilson(8), False)
test.assert_equals(am_i_wilson(9), False)
