C Program to Find the HCF of n Numbers

In this article, you will learn and get code for finding the HCF of n numbers. However, before you begin the program, I recommend that you first visit Find HCF of Two Numbers (if you haven't already). Because the program given here is related to the program in that article.

In C, find the HCF of n numbers

Now let's create a program to find the HCF of all the numbers given by the user at run-time.

#include<stdio.h>
#include<conio.h>
int main()
{
    int arr[10], n, mp, i, count;
    printf("Enter the Size: ");
    scanf("%d", &n);
    printf("Enter %d Numbers: ", n);
    for(i=0; i<n; i++)
        scanf("%d", &arr[i]);
    i=0;
    mp = arr[i];
    while(i<n)
    {
        if(mp<arr[i])
            mp = arr[i];
        i++;
    }
    while(1)
    {
        i=0;
        count=0;
        while(i<n)
        {
            if(arr[i]%mp==0)
                count++;
            i++;
        }
        if(count==n)
            break;
        else
            mp--;
    }
    printf("\nHCF(");
    for(i=0; i<(n-1); i++)
        printf("%d,", arr[i]);
    printf("%d) = %d", arr[i], mp);
    getch();
    return 0;
}

This program was built and runs in the Code::Blocks IDE. Here is the sample run:

Now supply the size, say 3, and enter any 3 numbers, say 8, 9, and 25. Press the ENTER key to see the following output:

Here is another sample run for two numbers:

This program is identical to the previous one, LCM of n Numbers in C. Except that we've switched the condition of the if block from:

mp%arr[i]==0

to

arr[i]%mp==0

and the statement from:

mp++;

to

mp--;

Why these two are reversed is discussed in LCM and HCF of Two Numbers in C. The brief description is:

• In the case of LCM, we have to find multiple (lowest common)
• In the case of HCF, we have to find factor (highest common)

And because multiples of a number are greater than the number, factors of a number are less than the number. I hope you are getting some idea about it. If not, then kindly visit:

• How to Find LCM
• How to Find HCF

C Quiz