isPrimeSearch.py

def checkForPrime1(possiblePrimeNumber):
    """ Checkes if a number is a prime. Returns true or false """
    if not isinstance(possiblePrimeNumber, int):
        return False

    if int(str(possiblePrimeNumber)[-1]) in (2, 4, 5, 6, 8, 0):
        if possiblePrimeNumber == 2:
            return True
        elif possiblePrimeNumber == 5:
            return True
        return False
    if possiblePrimeNumber == 1:
        return False
    # Vi antager at der kun skal testes for division med ulige tal, da all der kan divideres med et lige tal er frasorteret ovenfor som ikke prime
    # Since the number candidate at this stage is not divvisble by five (numbers ending in five is not a prime and have been skipped earlier), we want to only test for uneven numers that are nto five - hence the different loops
    if possiblePrimeNumber < 25:
        for currentDivider in range(3, round(possiblePrimeNumber ** 0.5) + 1, 10):
            if possiblePrimeNumber % currentDivider == 0:
                return False
    else:
        for currentDivider in range(3, round(possiblePrimeNumber ** 0.5) + 1, 10):
            if possiblePrimeNumber % currentDivider == 0:
                return False

        for currentDivider in range(7, round(possiblePrimeNumber ** 0.5) + 1, 10):
            if possiblePrimeNumber % currentDivider == 0:
                return False

        for currentDivider in range(19, round(possiblePrimeNumber ** 0.5) + 1, 10):
            if possiblePrimeNumber % currentDivider == 0:
                return False

        for currentDivider in range(11, round(possiblePrimeNumber ** 0.5) + 1, 10):
            if possiblePrimeNumber % currentDivider == 0:
                return False

    # All numbers have been checked - no divisor with mod 0 ==> it is a prime
    return True


def checkForPrime2(possiblePrimeNumber):
    """ Checkes if a number is a prime. Returns true or false """
    if int(str(possiblePrimeNumber)[-1]) in (2, 4, 5, 6, 8, 0):
        if possiblePrimeNumber == 2:
            return True
        elif possiblePrimeNumber == 5:
            return True
        return False

    for currentDivider in range(2, round(possiblePrimeNumber ** 0.5) + 1):
        if possiblePrimeNumber % currentDivider == 0:
            return False

    return True


def checkForPrime3(possiblePrimeNumber):
    """ Checkes if a number is a prime. Returns true or false """

    for currentDivider in range(2, round(possiblePrimeNumber ** 0.5) + 1):
        if possiblePrimeNumber % currentDivider == 0:
            return False

    return True


def checkForPrime4(possiblePrimeNumber):
    """ Checkes if a number is a prime. Returns true or false """

    for currentDivider in range(2, round(possiblePrimeNumber * 0.5) + 1):
        if possiblePrimeNumber % currentDivider == 0:
            return False

    return True


def checkForPrime5(possiblePrimeNumber):
    if not isinstance(possiblePrimeNumber, int):
        return False

    # Corner cases 
    if (possiblePrimeNumber <= 1):
        return False
    if (possiblePrimeNumber <= 3):
        return True

    if (possiblePrimeNumber % 2 == 0 or possiblePrimeNumber % 3 == 0):
        return False

    i = 5
    while (i * i <= possiblePrimeNumber):
        if (possiblePrimeNumber % i == 0 or possiblePrimeNumber % (i + 2) == 0):
            return False
        i = i + 6

    return True


def checkForPrime6(possiblePrimeNumber):
    if not isinstance(possiblePrimeNumber, int):
        return False

    # Corner cases 
    if (possiblePrimeNumber <= 1):
        return False
    if (possiblePrimeNumber <= 3):
        return True

    if (possiblePrimeNumber % 2 == 0 or possiblePrimeNumber % 3 == 0):
        return False

    i = 5
    while (i * i <= possiblePrimeNumber):
        if (possiblePrimeNumber % i == 0 or possiblePrimeNumber % (i + 6) == 0 or possiblePrimeNumber % (
                i + 12) == 0 or possiblePrimeNumber % (i + 18) == 0 or possiblePrimeNumber % (i + 24) == 0
                or possiblePrimeNumber % (i + 2) == 0 or possiblePrimeNumber % (
                        i + 2 + 6) == 0 or possiblePrimeNumber % (i + 2 + 12) == 0 or possiblePrimeNumber % (
                        i + 2 + 24) == 0 or possiblePrimeNumber % (i + 2 + 30) == 0):
            return False
        i = i + 36

    return True