#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <math.h>

#define SIZE 1000
int search(const unsigned char * t,int start,int end)
{
	pid_t p;
	int i, status, moitie = ceil((start + end) / 2);
	p = fork();
	switch(p){
		case -1:
			exit(1);
		case 0:
			for (i = 0; i < moitie; i++){
				if (t[i] == 0)
					exit(1);
			}
			exit(0);
		default:
			for (i = moitie; i <= end; i++){
				if (t[i] == 0)
					return 1;
			}
			wait(&status);
			return WEXITSTATUS(status);
		}
}

int main(int argc , char * argv[])
{
	int i;
	unsigned char arr[SIZE];

	srandom(time(NULL));

	for (i = 0; i < SIZE; i++)
		arr[i] = (unsigned char) (random() % 255) + 1;

	printf("Enter a number between 0 and %d: ", SIZE);
	scanf(" %d", &i);
	if (i >= 0 && i < SIZE) arr[i] = 0;

	if (search(arr,0,SIZE-1)) 
		printf("Found !\n");
	else 
		printf("Not found !\n");
	return EXIT_SUCCESS;
}