用C语言实现具有TCP和多线程的21点游戏

好的，我可以给您提供一个简单的实现。首先，您需要了解TCP和多线程的基本概念以及21点游戏的规则。接下来，我们来看一下具体的实现步骤：

1. 创建一个TCP服务器，监听客户端的连接请求；
2. 当有客户端连接时，创建一个新的线程来处理客户端的请求；
3. 在线程中，先发送欢迎消息和游戏规则给客户端；
4. 接下来，循环进行游戏，每轮分为以下几步：
a. 询问客户端是否要继续要牌；
b. 如果客户端要牌，则发一张牌给客户端，并计算当前手牌点数；
c. 如果客户端停止要牌，则计算庄家的手牌点数；
d. 根据点数判断胜负，并将结果发送给客户端；
5. 游戏结束后，关闭连接并退出线程。

下面是一个简单的代码示例，仅供参考：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#define PORT 9999
#define MAX_CLIENTS 10

int deck[52] = {1,2,3,4,5,6,7,8,9,10,10,10,10,1,2,3,4,5,6,7,8,9,10,10,10,10,1,2,3,4,5,6,7,8,9,10,10,10,10,1,2,3,4,5,6,7,8,9,10,10,10,10}; // 扑克牌
int deck_count = 52; // 剩余扑克牌数量

struct client_info {
    int sock_fd; // 客户端socket
    int score; // 手牌点数
};

void send_msg(int sock_fd, const char* msg) {
    write(sock_fd, msg, strlen(msg));
}

void* handle_client(void* arg) {
    struct client_info* client = (struct client_info*)arg;

    // 发送欢迎消息和游戏规则
    send_msg(client->sock_fd, "Welcome to 21 points game!\n");
    send_msg(client->sock_fd, "The goal of the game is to get as close to 21 as possible without going over.\n");
    send_msg(client->sock_fd, "Do you want to start the game? (y/n)\n");

    char buf[100];
    int recv_len;

    // 等待客户端开始游戏
    while ((recv_len = read(client->sock_fd, buf, 100)) > 0) {
        buf[recv_len] = '\0';
        if (strcmp(buf, "y\n") == 0) {
            break;
        } else if (strcmp(buf, "n\n") == 0) {
            close(client->sock_fd);
            free(client);
            return NULL;
        } else {
            send_msg(client->sock_fd, "Invalid input. Do you want to start the game? (y/n)\n");
        }
    }

    // 发牌
    int player_cards[10] = {0};
    int dealer_cards[10] = {0};
    int player_count = 0, dealer_count = 0;
    player_cards[player_count++] = deck[--deck_count];
    dealer_cards[dealer_count++] = deck[--deck_count];
    player_cards[player_count++] = deck[--deck_count];
    dealer_cards[dealer_count++] = deck[--deck_count];

    // 计算初始点数
    client->score = 0;
    for (int i = 0; i < player_count; i++) {
        client->score += player_cards[i];
    }

    // 发送初始手牌
    char msg[100];
    sprintf(msg, "Your cards: %d %d\n", player_cards[0], player_cards[1]);
    send_msg(client->sock_fd, msg);
    sprintf(msg, "Dealer's card: %d\n", dealer_cards[0]);
    send_msg(client->sock_fd, msg);

    // 循环进行游戏
    while (1) {
        // 询问是否要牌
        send_msg(client->sock_fd, "Do you want another card? (y/n)\n");
        while ((recv_len = read(client->sock_fd, buf, 100)) > 0) {
            buf[recv_len] = '\0';
            if (strcmp(buf, "y\n") == 0) {
                player_cards[player_count++] = deck[--deck_count];
                client->score += player_cards[player_count - 1];
                sprintf(msg, "Your card: %d\n", player_cards[player_count - 1]);
                send_msg(client->sock_fd, msg);
                break;
            } else if (strcmp(buf, "n\n") == 0) {
                break;
            } else {
                send_msg(client->sock_fd, "Invalid input. Do you want another card? (y/n)\n");
            }
        }

        // 判断是否爆牌
        if (client->score > 21) {
            send_msg(client->sock_fd, "Bust! You lose.\n");
            close(client->sock_fd);
            free(client);
            return NULL;
        }

        // 庄家继续要牌
        while (dealer_count < 5 && dealer_cards[dealer_count - 1] < 17) {
            dealer_cards[dealer_count++] = deck[--deck_count];
        }

        // 计算庄家点数
        int dealer_score = 0;
        for (int i = 0; i < dealer_count; i++) {
            dealer_score += dealer_cards[i];
        }

        // 判断胜负
        if (dealer_score > 21 || client->score > dealer_score) {
            send_msg(client->sock_fd, "You win!\n");
        } else if (client->score == dealer_score) {
            send_msg(client->sock_fd, "Push!\n");
        } else {
            send_msg(client->sock_fd, "You lose.\n");
        }

        // 关闭连接
        close(client->sock_fd);
        free(client);
        return NULL;
    }
}

int main() {
    int server_fd, client_fd;
    struct sockaddr_in server_addr, client_addr;
    socklen_t addr_len = sizeof(client_addr);
    pthread_t threads[MAX_CLIENTS];
    int thread_count = 0;

    // 创建服务器socket
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        perror("socket failed");
        exit(1);
    }

    // 绑定端口并开始监听连接请求
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(PORT);
    if (bind(server_fd, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("bind failed");
        exit(1);
    }
    if (listen(server_fd, MAX_CLIENTS) < 0) {
        perror("listen failed");
        exit(1);
    }

    // 接受客户端连接并创建线程处理请求
    while ((client_fd = accept(server_fd, (struct sockaddr*)&client_addr, &addr_len)) > 0) {
        struct client_info* client = (struct client_info*)malloc(sizeof(struct client_info));
        client->sock_fd = client_fd;
        if (pthread_create(&threads[thread_count++], NULL, handle_client, (void*)client) != 0) {
            perror("pthread_create failed");
            exit(1);
        }
        if (thread_count >= MAX_CLIENTS) {
            break;
        }
    }

    // 等待所有线程结束
    for (int i = 0; i < thread_count; i++) {
        pthread_join(threads[i], NULL);
    }

    // 关闭服务器socket
    close(server_fd);

    return 0;
}

这个实现可能还有很多需要改进的地方，比如错误处理、客户端输入的校验、加入多个玩家等等。但是这个示例可以帮助您理解如何使用C语言实现具有TCP和多线程的21点游戏。