Kod:
#include
#include
#include
#include

int
sum_of_digits (int number)
{
int temp = number;
int sum = 0;
while (temp)
{
sum += temp % 10;
temp /= 10;
}

return sum;
}

int
first_segment()
{
int xxxxx;
int xxx_min =1, xxx_max = 366;
int last_two_min = 3, last_two_max = 95;
int xxx = xxx_min + rand() % (xxx_max-xxx_min);
int last_two = last_two_min + rand() % (last_two_max - last_two_min);

xxxxx = (xxx * 100) + last_two;
return xxxxx;

}

int
third_segment ()
{
int xxxxx;
int sum;
int last;

do
{
xxxxx = rand() % 99999;
sum = sum_of_digits(xxxxx);
last = 7-(sum%7);
}
while(last == 0 || last == 8);

return xxxxx * 10 + last;
}

int
fourth_segment()
{
int xxxxx;
xxxxx = rand() % 99999;

return xxxxx;
}

int
main()
{
srand(time(NULL));
int first_seg, third_seg, fourth_seg;

first_seg = first_segment();
third_seg = third_segment();
fourth_seg = fourth_segment();
printf("%05d-OEM-%07d-%04d",first_seg, third_seg,fourth_seg);

return EXIT_SUCCESS;


}