So this article is for people who already know basics of C

// program to find biggest number in an array using pointer
#include <stdio.h>
void bigg(int *x);
int main()
{
    int i;
    int a[10];

    printf("enter the number: ");
    for (i = 0; i<=9; i++)
    {
        scanf("%d",&a[i]);
    }

     bigg(a);


}

void bigg (int *x)
{
    int i,temp;

   temp = *(x + 1);

    for (i = 0; i<=9; i++)
    {

        if (temp < x[i]) 
        {

               temp = x[i];
        }    

    }
    printf("The biggest number is: %d",temp);
}