Check whether a number can be expressed as a sum of two prime numbers In Python

               

    Check whether a number can be expressed as a sum of two prime numbers In Python

For example, the number 34 is given as input.

34 = 3 + 31
34 = 5 + 29
34 = 11 + 23
34 = 17 + 17

Program:

# Python program to check whether a number can be expressed as a sum of two prime numbers

def prime(n):

    isPrime = 1

    for i in range (2,int(n/2),1):

        if(n % i == 0):

            isPrime = 0

            break

    return isPrime

n = int(input("Enter a number : "))

f = 0;

i = 2

for i in range (2,int(n/2),1):

    if(prime(i) == 1):

        if(prime(n-i) == 1):

            print(n,"can be expressed as the sum of",i,"and",n-i)

            f = 1;

if (f == 0):

    print(n,"cannot be expressed as the sum of two prime numbers")

OutPut:

Enter a number : 34

34 can be expressed as the sum of 3 and 31

34 can be expressed as the sum of 5 and 29

34 can be expressed as the sum of 11 and 23

Enter a number : 35

35 can be expressed as the sum of 4 and 31

Enter a number : 37

37 cannot be expressed as the sum of two prime numbers