CODEWITHSUNDEEP
carraysgreatest-common-divisor
Krystal Phuar
Krystal Phuar

Reputation: 1

Finding GCD using arrays in C

Hi I am trying to write a code in C to find the GCD for more than 2 numbers. However, when I compile and run the code, the GCD is always 0. Would appreciate if anyone can help. Thank you.

#include <stdio.h>

static int gcd(int x, int y)
{
  int r;
  if (x <= 0 || y <= 0)
    return 0;

  while ((r = x % y) != 0)
    {
      x = y;
      y = r;
    }
    return y;
}

int main (void)
{
  int A[5];
  int g = A[0];
  int i;
  int n;

  printf ("How many elements are there? \n")
  scanf ("%d", &n);

  printf ("Input the elements. \n");

  for (i = 0; i < n; i++)
    {
      scanf ("%d", &A[i]);
    }

  for (i = 1; i < n; i++)
    g = gcd(g, A[i]);

    printf ("GCD is: %d \n");

return 0;
}

Upvotes: 0

Views: 1738

Answers (2)

Timʘtei
Timʘtei

Reputation: 765

You need a ; after the first printf. You need to declare A with n elements after you read the number of elements n. You have to write the g after ", in your last printf.

This is how I think your main should look like:

int main (void)
{
    int i;
    int n;

    printf ("How many elements are there? \n");
    scanf ("%d", &n);
    int A[n];

    printf ("Input the elements. \n");
    for (i = 0; i < n; i++)
    {
      scanf ("%d", &A[i]);
    }

    int g = A[0];
    for (i = 1; i < n; i++)
        g = gcd(g, A[i]);

    printf ("GCD is: %d", g);

    return 0;
}

Upvotes: 0

David Schwartz
David Schwartz

Reputation: 182819

You set g equal to A[0] before you set A[0] to any particular value.

Upvotes: 2

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