用c++中写出客户端和服务端代码利用udp协议引入txt文档进行机器人一问一答，而不是直接把文档的所有内容打印出来。

以下是一个简单的客户端和服务端代码，用于利用UDP协议进行机器人一问一答，并从txt文档中读取问题和答案。该程序的工作流程如下：

1. 服务端首先读取txt文档中的数据，并将问题和答案存储在map中。
2. 客户端向服务端发送一个问题。
3. 服务端接收到问题后，从map中查找对应的答案，并将答案发送回客户端。
4. 客户端接收到答案后打印出来，然后再次向服务端发送另一个问题，重复以上步骤。

服务端代码：

#include <iostream>
#include <fstream>
#include <string>
#include <map>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib")

using namespace std;

int main()
{
    // 初始化Winsock
    WSADATA wsaData;
    int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != 0) {
        cout << "WSAStartup failed: " << iResult << endl;
        return 1;
    }

    // 创建socket
    SOCKET serverSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (serverSocket == INVALID_SOCKET) {
        cout << "socket failed: " << WSAGetLastError() << endl;
        WSACleanup();
        return 1;
    }

    // 绑定socket到本地地址和端口
    sockaddr_in localAddr;
    localAddr.sin_family = AF_INET;
    localAddr.sin_port = htons(8888);
    localAddr.sin_addr.s_addr = INADDR_ANY;
    iResult = bind(serverSocket, (sockaddr*)&localAddr, sizeof(localAddr));
    if (iResult == SOCKET_ERROR) {
        cout << "bind failed: " << WSAGetLastError() << endl;
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    // 从txt文档中读取问题和答案，并存储在map中
    ifstream infile("qa.txt");
    map<string, string> qaMap;
    string line;
    while (getline(infile, line)) {
        string question = line.substr(0, line.find(","));
        string answer = line.substr(line.find(",") + 1);
        qaMap[question] = answer;
    }
    infile.close();

    // 循环接收和处理客户端请求
    while (true) {
        char recvBuf[1024];
        sockaddr_in clientAddr;
        int clientAddrLen = sizeof(clientAddr);

        // 接收客户端请求
        iResult = recvfrom(serverSocket, recvBuf, sizeof(recvBuf), 0, (sockaddr*)&clientAddr, &clientAddrLen);
        if (iResult == SOCKET_ERROR) {
            cout << "recvfrom failed: " << WSAGetLastError() << endl;
            closesocket(serverSocket);
            WSACleanup();
            return 1;
        }

        // 查找答案并发送回客户端
        string question(recvBuf, iResult);
        map<string, string>::iterator it = qaMap.find(question);
        string answer = "Sorry, I don't know.";
        if (it != qaMap.end()) {
            answer = it->second;
        }
        iResult = sendto(serverSocket, answer.c_str(), answer.length(), 0, (sockaddr*)&clientAddr, clientAddrLen);
        if (iResult == SOCKET_ERROR) {
            cout << "sendto failed: " << WSAGetLastError() << endl;
            closesocket(serverSocket);
            WSACleanup();
            return 1;
        }
    }

    // 关闭socket和清理Winsock
    closesocket(serverSocket);
    WSACleanup();
    return 0;
}

客户端代码：

#include <iostream>
#include <string>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib")

using namespace std;

int main()
{
    // 初始化Winsock
    WSADATA wsaData;
    int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != 0) {
        cout << "WSAStartup failed: " << iResult << endl;
        return 1;
    }

    // 创建socket
    SOCKET clientSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (clientSocket == INVALID_SOCKET) {
        cout << "socket failed: " << WSAGetLastError() << endl;
        WSACleanup();
        return 1;
    }

    // 设置服务器地址和端口
    sockaddr_in serverAddr;
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(8888);
    serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");

    // 循环发送和接收消息
    while (true) {
        // 发送问题
        string question;
        cout << "Please enter your question: ";
        getline(cin, question);
        iResult = sendto(clientSocket, question.c_str(), question.length(), 0, (sockaddr*)&serverAddr, sizeof(serverAddr));
        if (iResult == SOCKET_ERROR) {
            cout << "sendto failed: " << WSAGetLastError() << endl;
            closesocket(clientSocket);
            WSACleanup();
            return 1;
        }

        // 接收答案
        char recvBuf[1024];
        int serverAddrLen = sizeof(serverAddr);
        iResult = recvfrom(clientSocket, recvBuf, sizeof(recvBuf), 0, (sockaddr*)&serverAddr, &serverAddrLen);
        if (iResult == SOCKET_ERROR) {
            cout << "recvfrom failed: " << WSAGetLastError() << endl;
            closesocket(clientSocket);
            WSACleanup();
            return 1;
        }

        // 打印答案
        string answer(recvBuf, iResult);
        cout << "Answer: " << answer << endl;
    }

    // 关闭socket和清理Winsock
    closesocket(clientSocket);
    WSACleanup();
    return 0;
}

注意：在运行该程序之前，需要在同一目录下创建一个名为“qa.txt”的txt文档，并将问题和答案以逗号分隔的形式写入该文档中。例如：

What is your name?,My name is Robot.
What is the time now?,It is 2:30 PM.

另外，该程序仅为示例代码，可能存在一些潜在的问题和安全隐患，实际使用时需要进行更加完善的测试和优化。