Poincare Recurrence with Two Jars

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

int draw(const int, const int);

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

    int balls= 20;

    int urns[balls][2];

    //initialize urns
    for (int i= 0; i < balls; ++i){
        urns[i][0]= 1;  //first urn
        urns[i][1]= 0;  //second urn
    }

    int ktr1= balls, ktr2= 0, ran= 0, finish= 0;
    long long unsigned int iterCount= 0;

    do{
        ran= ( draw(1, balls)) -1;

        //visualize urns pre-action
        printf("\nUrn 1: |");
        for(int x=0 ; x<balls; ++x)
            printf("%d|", urns[x][0]);


        printf("\nUrn 2: |");
        for(int y=0 ; y<balls; ++y)
            printf("%d|", urns[y][1]);

        printf("\n-------------------\n");


        //move ball to urn 2
        if( urns[ran][0] == 1){
            //move ball
            urns[ran][0]= 0;    //first urn
            urns[ran][1]= 1;    //second urn
            //adjust ball counters
            --ktr1;
            ++ktr2;

        }
        //move ball to urn 1
        else{
            //move ball
            urns[ran][0]= 1;    //first urn
            urns[ran][1]= 0;    //second urn
            //adjust ball counters
            ++ktr1;
            --ktr2;
        }

        //increment iteration counter
        ++iterCount;

        //visualize urns
//      printf("\nUrn 1: |");
//      for(int x=0 ; x<balls; ++x)
//          printf("%d|", urns[x][0]);
//
//
//      printf("\nUrn 2: |");
//      for(int y=0 ; y<balls; ++y)
//          printf("%d|", urns[y][1]);
//
//      printf("\n-------------------\n");

        //end if all balls are in one side
        if(ktr1 == balls || ktr2 == balls) finish= 1;

    }while(finish != 1);

    printf("\n\n\tFINISHED, iterations: %lld\n\n", iterCount);

    _exit(0);
}


/* Purpose: generates random number from range
 * In : low and upepr bound
 * Out: random number
 */
int draw(const int low, const int high){


    return (rand() % high + 1);
}