simple multithreading with semaphore posix c++

sem_multithread.cpp

#include <iostream>
#include <unistd.h>
#include <thread>
#include <vector>
#include <signal.h>
#include <semaphore.h>

using namespace std;

vector<thread*> th;
static sem_t semaphore;

void quit(int q)
{
        cout << "End" << endl;
        exit(0);
}

void event(int index)
{
        while(1)
        {
                static long count = 0;
                sem_wait(&semaphore);
                cout << "Thread:" << index << " Count:" << count << endl;
                count++;
                sem_post(&semaphore);
                usleep(10000);
        }
}

int main(int argc, char ** argv)
{
        if(argc<2)
        {
                cerr << "Error: num-thread" << endl;
                exit(0);
        }
        int MAX_THREAD=atoi(argv[1]);
        signal(SIGINT,quit);
        if (sem_init(&semaphore, 0, 1) == -1)
                cerr << "Error: semaphore" << endl;
        for(int i = 0; i < MAX_THREAD; i++)
        {
                thread* t = new thread(event, i);
                th.push_back(t);
        }
        for(int i = 0; i < th.size(); i++)
                th[i]->join();
        return 0;
}