How can I shuffle a vector with structures? C

Question

I need to shuffle domino pieces on a function, and I’m having trouble.

void baralhar(int domino[])
{
    srand(time(NULL));
    for (int i=1;i<=29;i++)
    {
        int r = rand() % 28;

        int aux = domino[i];
        domino[i] = domino[r];
        domino[r] = aux;
    }
}