typedef struct
{
    pthread_t tid;
    int inicio;
    int fim;
    long double pi;
} pi_struct;

void* calcula_pi(void *args);

int main(int argc, int * argv[])
{
    //pi_struct *aux = (pi_struct *)args;
    struct pi_struct aux[10];
    int aux_inicio = 0;
    int aux_fim = 100;
    int counter = 2;
    int i;

    for(i = 0; i < 10; i++)
    {
        aux[i].inicio = aux_inicio;
        aux[i].fim = aux_fim;

        pthread_create(&aux[i], NULL, calcula_pi, (void*)&aux[i]);
        aux_inicio = aux_fim;
        aux_fim = aux_fim * counter;
        counter++;
    }

    printf("\nPi = %.20Lf\n", aux->pi);

    return 0;
}

void* calcula_pi(void *args)
{
    double temp;
    pi_struct *aux = (pi_struct *)args;

    for(; aux->inicio < aux->fim; aux->inicio++)
    {
        temp = (pow((int)-1, (int)aux->inicio));
        aux->pi += (temp / ((2 * aux->inicio) + 1));
    }

    pthread_exit(NULL);
}