How can i make third argument optional in this code ?
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
int sum(int n, ...) {
int i = 0, s = 0;
va_list args;
va_start(args, n);
for (; i < n ; i++) {
s += va_arg(args, int);
}
va_end(args);
return s;
}
int main() {
printf("%d\n", sum(5, 1, 2, 3, 4, 8));
}