Challenge 🏆🏆 Represent a composite number as a sum of two prime numbers.

Question

Its a proof that any composite number can be represented as the sum of two prime number.

eg. 8 = 5+3;
22 = 19 + 3; or 17 + 5;

Your program should find all the pairs of prime numbers whose sum is equal to n where n is any composite number.

Answer 1

https://code.sololearn.com/cxa7S9GmzfSH/?ref=app

Answer 2

https://code.sololearn.com/czTIFjtzn23y/?ref=app

Answer 3

Not every composite number is the sum of two primes. Counterexamples: Every odd composite number n, such that n-2 is not prime (27, 35, 51...).

We actually don't know whether every even number bigger than two is the sum of two primes. Every number we looked at has that property, but that does not constitute a proof, as we only checked for a finite subset of an infinite set of numbers.

https://en.m.wikipedia.org/wiki/Goldbach%27s_conjecture

Answer 4

fixed
And now works better
https://code.sololearn.com/cJmrEXAB26e9/?ref=app

Answer 5

https://code.sololearn.com/crMUlLUT6Uqw/?ref=app

Answer 6

oneliner
https://code.sololearn.com/cLh2BoZsg3Sy/?ref=app

Answer 7

here's the most straightforward version I could make in c++ :
https://code.sololearn.com/c9ooluWHmO42/?ref=app

Answer 8

https://code.sololearn.com/clD3j87zJXPw/?ref=app

Answer 9

11 + 11 is also equal to 22