C Program Code For Finding HCF / GCD of N entered numbers (Highest Common Factor == Greatest Common Divisor)

/* The following C Program returns the HCF/GCD of N entered numbers. It uses an array to stored the numbers entered by users. The program will display GDC/HCF not exist when a character is entered instead of an integer */

#include<stdio.h>
#include<conio.h>

int n=0;
int HCF(int *x)
{
   int a[100],c,d,m=0,i=1,tt=0,t=0;
   while(tt<n)
   {
                   a[tt]=*x;
                   x++;
                   tt++;
   }
    while(t<n)
    {
              if(a[t]==0)
              {
                   printf("\n GCD/HCF of the given numbers is : 0");
                   goto a;
              }
              t++;
    }         
   while(m<n)
   {
           while(i<n)
           {
              if(a[m]>a[i])
              {
                           c=a[m];
                           a[m]=a[i];
                           a[i]=c;
              }
              i++;
           }
           m++;
   }
   c=a[0];
   d=n-1;    
   while(c>1)
   {
             while(a[d]%c==0)
             {
                             if(d>1)
                             {
                                    d--;
                                    continue;
                             }
                             else
                             return c;
             }
             c--;
             if(c==1)
             return -1;
   }
   a:
         return -2;
}


int main()
{
    int x[100],z=0;
    printf("\nFor How Many Numbers You Want To Find GCD/HCF?: ");
    scanf("%d",&n);
    printf("\nEnter %d numbers to find their GCD/HCF\n", n);
    while(z<n)
    {
            scanf("%d",&x[z]);
            z++;
    }

    x[n]=HCF(x);
    if(x[n]==-1)
    {
                printf("\n HCF/GCD doesn't exist");
    }
    else if(x[n]==-2)
    {
      printf("\nThe GCD/HCF of given numbers is : 1");         
    }
    else
    {
                printf("GCD/HCF of given numbers is : %d",x[n]);
    }
    getch();
    return 0;
}

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