[PWŚS] UDP Broadcast

#pragma comment(lib, "Ws2_32.lib")
#define _CRT_SECURE_NO_WARNINGS

#include <windows.h>
#include <conio.h>
#include <stdio.h>
#include <time.h>
#include <string>
#include <vector>

using namespace std;

int main() {
    WSADATA wsa;  WSAStartup(MAKEWORD(2, 2), &wsa);
    SOCKET sockout = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    SOCKET sockin = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    SOCKADDR_IN broadcast, receive;
    broadcast.sin_addr.s_addr = htonl(INADDR_BROADCAST);
    broadcast.sin_family = receive.sin_family = AF_INET;
    broadcast.sin_port = receive.sin_port = htons(5001);
    receive.sin_addr.s_addr = htonl(INADDR_ANY);
    bind(sockout, (SOCKADDR*)&broadcast, sizeof(broadcast));
    bind(sockin, (SOCKADDR*)&receive, sizeof(receive));
    int one = 1;
    setsockopt(sockout, SOL_SOCKET, SO_BROADCAST, (char*)&one, sizeof(one));

    char buffer[200] = "";
    char random[61];
    int length, wynik;
    int inSize = sizeof(receive);
    fd_set set;
    timeval timeout;
    bool exists;

    vector<string> hosty;

    while (1) {
        if (_kbhit()) { if (_getch() == VK_ESCAPE) {
            sendto(sockout, "KONIEC", strlen("KONIEC"), 0, (SOCKADDR*)&broadcast, sizeof(broadcast));
            break;
        }
        else {
            srand(clock());
            length = 20 + rand() % 41;
            for (int i = 0; i < length; ++i) {
                srand(clock() + i*i);
                random[i] = 32 + rand() % 95;
            }
            random[length] = '\0';
            strcpy(buffer, "Piotr Zaporowski ");
            strcat(buffer, random);
            sendto(sockout, buffer, strlen(buffer), 0, (SOCKADDR*)&broadcast, sizeof(broadcast));
            }
        }
        else {
            timeout.tv_sec = 0;
            timeout.tv_usec = 100 * 1000;
            FD_ZERO(&set);
            FD_SET(sockin, &set);
            wynik = select(FD_SETSIZE, &set, NULL, NULL, &timeout);
            if (wynik > 0) {
                memset(buffer, 0, sizeof(buffer));
                recvfrom(sockin, buffer, sizeof(buffer), 0, (SOCKADDR*)&receive, &inSize);
                if (!strcmp(buffer, "KONIEC")) {
                    for (int i = hosty.size() - 1; i >= 0; --i) {
                        if (hosty[i] == inet_ntoa(receive.sin_addr)) {
                            hosty.erase(hosty.begin() + i);        break;
                        }
                    }
                } else {
                    exists = false;
                    for (int i = 0; i < hosty.size(); ++i) {
                        if (hosty[i] == inet_ntoa(receive.sin_addr)) {
                            exists = true;
                            break;
                        }
                    }
                    if (!exists) hosty.push_back(inet_ntoa(receive.sin_addr));
                    for (int i = 0; i < hosty.size(); ++i) {
                        printf("%s", hosty[i].c_str());
                        if (i == hosty.size() - 1) printf("\n");
                        else printf(", "); }
                    printf("%s: %s\n\n", inet_ntoa(receive.sin_addr), buffer);
                }
            }
        }
    }

    shutdown(sockin, 2);
    shutdown(sockout, 2);
    closesocket(sockin);
    closesocket(sockout);

    WSACleanup();
}