unique_rng.c

#define RAND_PERIOD 65536
unsigned int *rand_array;

int init_rand(){
    int i;
    unsigned int r1, r2, temp;
    rand_array = (unsigned int*) malloc(RAND_PERIOD*sizeof(unsigned int));

    for(i=0; i<RAND_PERIOD; i++)
        rand_array[i] = i;

    // Shuffle array
    for(i=0; i<RAND_PERIOD; i++){
        r1 = rand() % RAND_PERIOD;
        r2 = rand() % RAND_PERIOD;
        temp = rand_array[r1];
        rand_array[r1] = rand_array[r2];
        rand_array[r2] = temp;
    }
    return 0;
}

int destroy_rand(){
    free(rand_array);
    return 0;
}

unsigned int unique_random_number(){
    static int rand_array_index=0;
    unsigned int temp;
    temp = rand_array[rand_array_index];
    rand_array_index++;
    return temp;
}