#include <pthread.h>
#include <iostream>

using namespace std;

volatile int a = 0, b = 0;

void* suma(void*)
{
	while (true)
	{
		a = a + 1;
		b = b + 1;
	}
	return NULL;
}

void* resta(void*)
{
	while (true)
	{
		a = a - 1;
		b = b - 1;
	}
	return NULL;
}

void* pinta(void*)
{
	while (true)
	{
		cout << "a = " << a << "\t b = " << b << endl;
		pthread_yield();
	}
	return NULL;
}

int main()
{
	pthread_t ids, idr, idp;

	pthread_create(&ids, NULL, suma, NULL);
	pthread_create(&idr, NULL, resta, NULL);
	pthread_create(&idp, NULL, pinta, NULL);

	pthread_join(ids, NULL);
	pthread_join(idr, NULL);
	pthread_join(idp, NULL);
}