25-C01P14

C01P14 - Goldbach conjecture

Implement a function, called goldbach which takes an integer n, and returns a list of tuples, that is the goldbach conjecture for the given number.

The Goldbach conjecture states:

Every even integer greater than 2 can be expressed as the sum of two primes.

Keep in mind that there can be more than one combination of two primes, that sums up to the given number.

In case an odd integer is given, return None.

The result should be sorted by the first item in the tuple.

For example:

• 4 = 2 + 2
• 6 = 3 + 3
• 8 = 3 + 5
• 10 = 3 + 7 = 5 + 5
• 100 = 3 + 97 = 11 + 89 = 17 + 83 = 29 + 71 = 41 + 59 = 47 + 53

Signature

def goldbach(n):
    pass

Examples

goldbach(4) == [(2,2)]
goldbach(6) == [(3,3)]
goldbach(8) == [(3,5)]
goldbach(10) == [(3,7), (5,5)]
goldbach(100) == [(3, 97), (11, 89), (17, 83), (29, 71), (41, 59), (47, 53)]
goldbach(5) is None