calling structure into main function

Question

I am writing code to find two prime numbers. For this I need to return two values from the function primefactor(). I am using a structure to return the two values.

#include <stdio.h>
#include<stdbool.h>

struct tuple  {
    long int prime1,prime2;
};

typedef struct tuple primefind;

bool isPrime(int n) 
{ 
    // Corner case 
    if (n <= 1)  return false; 
  
    // Check from 2 to n-1 
    for (int i=2; i<n; i++) 
        if (n%i == 0) 
            return false; 
  
    return true; 
} 

long int nextPrime(long int n)
{
    // Base case
    if (n <= 1)
        return 2;
    long int prime = n;
    bool found = false;
    // Loop continuously until isPrime returns
    // true for a number greater than n
    while (!found)
    {
        prime++;
        if (isPrime(prime))
            found = true;
    }
    return prime;
}

primefind primeFactor(long int n)
{
    primefind tuple1;
    long int p, q;

    p = 2;
    while (p <= (n / p))
    {
        if (n % p == 0)
        {
            q = n / (p);
            break;
        }
        p = nextPrime(p);
    }

    tuple1.prime1 = p;
    tuple1.prime2 = q;
    return tuple1;
}


int main()
{
    
    
    return 0;
}

How could I print the value of p,q in the main function which are the two variables of primeFactor function?

Thank you.

Answer 1

Anything wrong with the obvious solution?

primefind primes = primeFactor(n);
printf("%ld %ld\n", primes.prime1, primes.prime2);

You may also consider changing your approach and using function parameters for your return values:

void primeFactor(long int n, long int *prime1, long int *prime2)
{
    // ...
    *prime1 = 7;
    *prime2 = 11;
    return;
}

Also please consider only checking factors up to the square root of your number.