Q) all prime numbers can be written in the form of 6m+1 or 6m-1 for some m>=1. write a program to print "Cannot be decided" if the above property is fulfilled or "Composite number" otherwise.
I can't figure out how to put the given statement into a code. i tried a few codes (such as the one given below) but nothing is striking me. Please help. my code is in the pastebin link because formatting here isn't working properly
n=int(input())
for m in range(1,n):
if n==6*m+1 or n==6*m-1:
print("Cannot be determined")
else:
print("Composite number")
break
There is no point to having a loop, it's just unnecessary work and it's much less clear. Every prime p greater than 3 must be of the form 6m + 1 or 6m - 1 for some integer m. That's equivalent to saying that p = 1 mod 6 or p = -1 = 5 mod 6. So just make that the test.
n=int(input('Enter value to test for primality: '))
# assume n > 3
if n % 6 in (1, 5):
print("Cannot be determined")
else:
print("Composite number")