#include <stdio.h>
#include <stdlib.h>

double funkcja(int i, int n)
        {
        double p = ((i*i)-12);
        double l = (p*p*p);
        double m = (n*n*n*i*i*i);
        return l/m;
        }

int main(int argc, char* argv[])
{
        int n = atoi(argv[1]);
        int k = atoi(argv[2]);
        int j=0;
        int i=1;
        double suma, e, tmp;
        int pipefd[2];
        pid_t pid;

        if(pipe(pipefd) == -1)
        {
                perror("err pipe\n");
                exit(EXIT_FAILURE);
        }

        while(i<=n)
        {

                for(j=0; j<k; j++)
                {
                        if(i>n)
                                break;
                        pid = fork();

                        if(pid == -1)
                        {
                                perror("err fork\n");
                                exit(EXIT_FAILURE);
                        }

                        if(pid==0)
                        {
                                e=funkcja(i,n);
                                write(pipefd[1], &e, sizeof(double));
                                exit(EXIT_SUCCESS);
                        }
                        i++;
                }
        }

        close(pipefd[1]);
        while(read(pipefd[0], &tmp, sizeof(double)))
                suma+=tmp;
        printf("suma: %f\n", suma);
        return EXIT_SUCCESS;
}