#include<stdio.h>
#include<stdarg.h>
double average(int n, ...)
{
    va_list arg;
    int i = 0;
    double sum = 0;
    va_start(arg, n);
    for(i = 0; i < n; i++)
    {
        sum = sum + va_arg(arg, double);
    }
    va_end(arg);
    return sum / n;
}
int main()
{
    double a = 1.3
 
;
    double b = 2.5;
    double c = 3.7;
    double avg1 = average(2, a, b);
    double avg2 = average(3, a, b, c);
    printf("avg1 = %lf\n", avg1);
    printf("avg2 = %lf\n", avg2);
    system("pause");
    return 0;
}