Checks to see if a number is a prime in O(sqrt(n)). A number is prime if it has exactly two factors: 1 and itself. >>> is_prime(0) False >>> is_prime(1) False >>> is_prime(2) True >>> is_prime(3) True >>> is_prime(27) False >>> is_prime(87) False
(number: int)
| 7 | |
| 8 | |
| 9 | def is_prime(number: int) -> bool: |
| 10 | """Checks to see if a number is a prime in O(sqrt(n)). |
| 11 | |
| 12 | A number is prime if it has exactly two factors: 1 and itself. |
| 13 | |
| 14 | >>> is_prime(0) |
| 15 | False |
| 16 | >>> is_prime(1) |
| 17 | False |
| 18 | >>> is_prime(2) |
| 19 | True |
| 20 | >>> is_prime(3) |
| 21 | True |
| 22 | >>> is_prime(27) |
| 23 | False |
| 24 | >>> is_prime(87) |
| 25 | False |
| 26 | >>> is_prime(563) |
| 27 | True |
| 28 | >>> is_prime(2999) |
| 29 | True |
| 30 | >>> is_prime(67483) |
| 31 | False |
| 32 | """ |
| 33 | |
| 34 | # precondition |
| 35 | assert isinstance(number, int) and (number >= 0), ( |
| 36 | "'number' must been an int and positive" |
| 37 | ) |
| 38 | |
| 39 | if 1 < number < 4: |
| 40 | # 2 and 3 are primes |
| 41 | return True |
| 42 | elif number < 2 or not number % 2: |
| 43 | # Negatives, 0, 1 and all even numbers are not primes |
| 44 | return False |
| 45 | |
| 46 | odd_numbers = range(3, int(math.sqrt(number) + 1), 2) |
| 47 | return not any(not number % i for i in odd_numbers) |
| 48 | |
| 49 | |
| 50 | def next_prime(value, factor=1, **kwargs): |
no outgoing calls
no test coverage detected