//Michal A Wilk

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

#define RMIN -15
#define RMAX 15

double fun( double x )
{
	return ( 8*pow(x,5) - 2*pow(x,4) + 15*pow(x,2) - 24*x + 18 );
}

int main( int argc, char* argv[] )
{
	printf("start parent\n");
	if(argc != 3)
		return 1;
	double n = atof(argv[1]);
	int k = atoi(argv[2]);
	int pipecp[2];
	double range = 30.0/(double)k;
	printf("RANGE %f\n",range);
	pipe( pipecp );
	int i;
	for( i = 0; i < k; ++i )
	{
		int forkval = fork();
		if( forkval < 0 )
			return 2;
		if( forkval == 0 )
		{
			printf("child created\n");
			double min = RMIN + range*i;
			double max = min + range;
			double result = 0.0;
			if( min >= RMAX )
			{
				printf("%f - %f [%f] : %f\n",min,max,range,result);
				write( pipecp[1], &result, sizeof(result) );
				exit(0);
			}
			if( max > RMAX )
				max = RMAX;
			double j;

			for( j = min; j < max; j += n )
				result += ( ( fun(j+n) + fun(j) )/2 * n);
			printf("%f - %f [%f] : %f\n",min,max,range,result);
			write( pipecp[1], &result, sizeof(result) );
			printf("child exit\n");
			exit(0);
			break;
		}
		printf("loop iterate\n");
	}
	printf("loop exit\n");
	while( wait(0) > 0) {}
	printf("children dead\n");
	double sum = 0;
	double part;
	for( i = 0; i < k; ++i )
	{
		read( pipecp[0], &part, sizeof(part) );
		printf("%f\n", part);
		sum += part;
	}
	printf("WYNIK KONCOWY : %f\n", sum);
	return 0;
}