Выбрать 10 случайных неповторяющихся карт из колоды - C (СИ)

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
 
#define SUITS_COUNT 4
#define VALUES_COUNT 13
#define CARDS_IN_DECK (SUITS_COUNT * VALUES_COUNT)
#define CARDS_PER_PLAYER 5
#define NUMBER_OF_PLAYERS 4
    
typedef struct CARD {
    const char * value;
    const char * suit;
} card_t;
 
/*S - Spades, C - Clubs, D - Diamonds, H - Hearts*/
card_t deck[CARDS_IN_DECK] = {
    {"2", "S"}, {"3", "S"}, {"4", "S"}, {"5", "S"}, {"6", "S"}, {"7", "S"}, {"8", "S"}, {"9", "S"}, {"10", "S"}, {"J", "S"}, {"Q", "S"}, {"K", "S"}, {"A", "S"}, 
    {"2", "C"}, {"3", "C"}, {"4", "C"}, {"5", "C"}, {"6", "C"}, {"7", "C"}, {"8", "C"}, {"9", "C"}, {"10", "C"}, {"J", "C"}, {"Q", "C"}, {"K", "C"}, {"A", "C"}, 
    {"2", "D"}, {"3", "D"}, {"4", "D"}, {"5", "D"}, {"6", "D"}, {"7", "D"}, {"8", "D"}, {"9", "D"}, {"10", "D"}, {"J", "D"}, {"Q", "D"}, {"K", "D"}, {"A", "D"}, 
    {"2", "H"}, {"3", "H"}, {"4", "H"}, {"5", "H"}, {"6", "H"}, {"7", "H"}, {"8", "H"}, {"9", "H"}, {"10", "H"}, {"J", "H"}, {"Q", "H"}, {"K", "H"}, {"A", "H"}
};
int top;
 
/* бестолковая функция для перемешивания карт */
int rndcmp(const void * a, const void * b) {
    return rand() - rand();
}
/* перемешивание колоды + установка на первую карту значения вершины */
void shuffle_deck(void) {
    top = 0;
    qsort(deck, CARDS_IN_DECK, sizeof(card_t), rndcmp);
}
 
/* выдача карты из колоды */
card_t * get_card(void) {
    return ( top < 0 || top >= CARDS_IN_DECK ) ? NULL : &deck[top++];
}
 
/* печать карты */
void print_card(const card_t * card) {
    printf("|%2s %s| ", card->value, card->suit);
}
 
/* функции для сравнения карт */
/* по значению */
int compare_by_value(const card_t * a, const card_t * b) {
    static const char values[] = "2345678910JQKA";
    return strstr(values, a->value) - strstr(values, b->value);
}
/* по масти (в покере вещь ненужная, только для красивости вывода) */
int compare_by_suit(const card_t * a, const card_t * b) {
    static const char suits[] = "SCDH";
    return strstr(suits, a->suit) - strstr(suits, b->suit);
}
/* по значению, за тем по масти, подходит для qsort */
int compare_cards(const void * a, const void * b) {
    card_t * ca = *(card_t**)a;
    card_t * cb = *(card_t**)b;
    int diff = compare_by_value(ca, cb);
    
    return ( diff ) ? diff : compare_by_suit(ca, cb);
}
 
#define PLAYER_NAME_LENGTH 64
typedef struct PLAYER {
    char name[PLAYER_NAME_LENGTH];
    card_t * cards[CARDS_PER_PLAYER];
} player_t;
 
int main(void) {
    player_t players[NUMBER_OF_PLAYERS];
    int nPlayer, nCard;
    
    srand(time(NULL));
    
    /* Имена для наглядности */
    for ( nPlayer = 0; nPlayer < NUMBER_OF_PLAYERS; ++nPlayer )
        sprintf(players[nPlayer].name, "Player #%d", nPlayer + 1);
    
    /* Раздача карт */
    shuffle_deck();
    for ( nCard = 0; nCard < CARDS_PER_PLAYER; ++nCard ) {
        for ( nPlayer = 0; nPlayer < NUMBER_OF_PLAYERS; ++nPlayer ) {
            if ( ! ( players[nPlayer].cards[nCard] = get_card() ) ) {
                fprintf(stderr, "ERROR! No more cards in deck!\n");
                exit(1);
            }
        }
    }
    
    /* Сортировка и вывод карт у игроков до обмена + обмен */
    printf("\nEnter string in form 00101 where 0 to keep card, 1 to change.\n\n");
    for ( nPlayer = 0; nPlayer < NUMBER_OF_PLAYERS; ++nPlayer ) {
        int cardsToChange;
        printf("%s\n", players[nPlayer].name);
        qsort(players[nPlayer].cards, CARDS_PER_PLAYER, sizeof(card_t*), compare_cards);
        for ( nCard = 0; nCard < CARDS_PER_PLAYER; ++nCard )
            print_card(players[nPlayer].cards[nCard]);
        printf("\n> ");
        scanf("%d", &cardsToChange);
        for ( nCard = CARDS_PER_PLAYER - 1; nCard >= 0; --nCard, cardsToChange /= 10 ) {
            if ( cardsToChange % 10 ) {
                if ( ! ( players[nPlayer].cards[nCard] = get_card() ) ) {
                    fprintf(stderr, "ERROR! No more cards in deck!\n");
                    exit(1);
                }
            }
        }
        printf("\n");
    }
    
    printf("\n\nAfter exchange:\n");
    for ( nPlayer = 0; nPlayer < NUMBER_OF_PLAYERS; ++nPlayer ) {
        int cardsToChange;
        printf("%s\n", players[nPlayer].name);
        qsort(players[nPlayer].cards, CARDS_PER_PLAYER, sizeof(card_t*), compare_cards);
        for ( nCard = 0; nCard < CARDS_PER_PLAYER; ++nCard )
            print_card(players[nPlayer].cards[nCard]);
        printf("\n\n");
    }
    
    exit(0);
}