#include <stdio.h>			//printf
#include <stdlib.h>			//random
#include <time.h>				//clock, time
#include <unistd.h>			//fork
#include <sys/types.h>	//clock_t type

int drawTicket(const int, const int);
void showUrns(int*, const int, const unsigned long long, const int);

int main(){
	srand(time(NULL));	//seed randomizer

	int finish= 0, balls= 10;
	int urns[balls];

	//initialize urn
	for (int i= 0; i < balls; ++i){	urns[i]= 0;	}

	int ktr1= balls, ticket= 0;
	unsigned long long nrDraws= 0;

	do{	
		ticket= (drawTicket(1,balls)) -1;	//draw a random ticket		
		showUrns(urns,balls,nrDraws,0);
		
		//move respective ball to other urn
		if(urns[ticket] == 0){
			urns[ticket]= 1;
			--ktr1;			
		}	else{
			urns[ticket]= 0;
			++ktr1;
		}
		
		++nrDraws;	//track number of draws		
		showUrns(urns,balls,nrDraws,1);	//display ball positions
		
		//Finish when balls are all in the first jar
		if(ktr1 == balls) finish= 1;				
	} while(!finish);

	printf("\n\tFINISHED, iterations: %llu\n\n", nrDraws);

	_exit(0);
}


/* Purpose: generates random number from range
 *   In : low, upper  bound
 *   Out: random number			*/
int drawTicket(const int low, const int high){
	return (low + (rand() % high) ) ;
}


/* Purpose: displays in which urn a ball is in
 *   In : urn array, nr of balls, nr of draws, show pre(0) or post(1) draw
 *   Out: none							*/
void showUrns(int *arrUrns, const int balls, const unsigned long long draws, const int post){
	int urn, b= balls;
	
	if (!post){	
		printf("\n  ## Balls location, draws:(%llu) ##", draws+1);
		printf("\n------------------------------------\n");
		printf(" pre-draw  : |");	
			
		for(int i= 0 ; i<balls; ++i){ 			
			printf("%d|", (arrUrns[i] == 0)? 1: 2);
		}	
	
	}else if (post){		
		printf("\n post-draw : |");
		
		for(int i=0 ; i<balls; ++i){
		printf("%d|", (arrUrns[i] == 0)? 1: 2);
		}
		
		printf("\n------------------------------------\n");
				
	}else{
		printf("\n\t/!\\ ERROR: no pre/post-draw selected /!\\");
	}
}