#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <signal.h>
 
double f(double x){
    return 8*pow(x, 5.0) - 2*pow(x, 4.0) + 15*pow(x,2.0) - 24*x + 18;
}
 
double area_f(int a, int b, int n){
   
 
    printf("DANE WEJ %i, %i, %i\n", a, b, n);
    double h = (b - a) / (double)n;
    double s = 0.0;
    double floor_a = f(a), floor_b;
    int i;
   
    for(i = 1; i <=n; i++){
        floor_b = f(a + h * i);
        s += (floor_a + floor_b);
        floor_a = floor_b;
    }
   
 
    printf("SMALL STUFF %f\n", (s * 0.5 * h));
   
    return s * 0.5 * h;
   
}
 
int main(int argc, char *argv[]){
   
    int pip[2];
    pipe(pip);
    int pid = 10;
    int iter = 0;
    int k = 3;
    int max_a = -15;
    int max_b = 15;
    int range = abs(max_a - max_b) / k;
    int current_a = max_a;
    int a;
    int b;
    int n = 1000;
   
    double area = 0.0;
    double temp_area = 0.0;
    int read_k_times = 0;
 
    int l = 0;
    int first = 0;
 
    for(l = 0; l < k; l++){
        if(pid>0){
            if(first == 0){
                a = -15;
                b = -5;
                first=1;
            }else{
                a = b;
                b += range;
            }
            pid = fork();
           
        }
    }
       
       
        if(pid == 0){
 
            double calc_area = area_f(a, b, n);
            printf("calc_area %f\n", calc_area);
            close(pip[0]);
            write(pip[1], &calc_area, sizeof(calc_area));
           
           
            //kid
        }else{
            printf ("ITER %i\n", iter);
            int m = 0;
            for(m = 0; m < k; m++){
                close(pip[1]);
                printf("I AM READING STUFF");
                read(pip[0], &temp_area, sizeof(temp_area));
                area += temp_area;
                read_k_times++;
            }
           
           
           
            printf("FINAL AREA %f\n", area);
           
           
            kill(0, SIGKILL);
                exit(0);
           
           
            //parent
        }
   
   
   
   
    return (0);
   
   
 
 
}