Monty Hall Simulator for 3 items

/**
* Monty Hall Simulator
* Shows the probabilty of getting the price if you do not change your choice or if you do
* The Program starts with a random "door" array, with two fails (0's) and one price (1)
* The "user" choices random position, then the program deletes one fail (turning it into -1)
* and the user changes his choice (successIfChange) and test whether he gets the price or not
* same test is done simultaneosly choicing not to change his choice ()
* then the success rate for both cases are shown for a  big amount of tries
* For customizing the numbr of tries, edit the NUMBER_OF_TRIES constant
* @author E.A [agua15@eresmas.com]
*/

int NUMBER_OF_TRIES=1000000;

/**
* Returns a random array of 3 positions with two fails(0's) and one price (1)
*/
int[] fillArray()
{
int[] myarray=new int[3];
int candidate= (int) ((Math.random ()*100) % 3);
myarray[candidate]=1;
for (int i=0;i<3;i++){
  if(myarray[i]!=1) myarray[i]=0;
}
return myarray;
}

/**
* Gets the position of the price ('1' value) for the current array
*/
int getPricePosition(int[] array)
{
for (int i=0;i<3;i++){
  if (array[i]==1) return i;
}
return -1;
}

/**
* Change user choice amongst the another unique valid choice
* @param guess user original guess
* @discarded forbidden choice as it was "revealed" by the program
* @myarray array with one price(1), one fail(0), and one discarded item (-1)
*/
int changePos(int guess,int discarded,int[] myarray)
{
for (int i=0;i<3;i++){
  if (i!=guess && i!=discarded) return i;
}
return -1;
}

/**
*  Trim door array with two valid positions,
*  one must be the price
*  and return the position of the discarded door
*  @param myarray original door array
*  @param myguess user guess of price
*  @one real position of price
*/
int getChoicedArray(int[] myarray,int myGuess,int one){
  int[] small= new int[3];
  boolean flag=true;
 for (int k=0;k<3;k++){
   small[k]=0; //default fill
  if (k==one) { // compulsory item, must not be discared
     small[k]=myarray[k]; //will be 1 ,otherwise algorithm is wrong
     if (small[k]!=1) return -1;// error, should never happen
   }else if(flag && k!=myGuess){ //discarded option
     small[k]=-1;
     flag=false; // do not enter this condition again
   }

  }
  // return position of discarded door
 for  (int i=0;i<3;i++){
   if (small[i]==-1)return i;
 }
 return -1; // error, should never happen
}

/**
*  Main flow of the program:
*  get the original door array . Example: [0,1,0] two fails and one price
*  get user's choice: (possible values: 0,1,2). For Example: 1
*  Discard a fail : Example: [-1,1,0]
*  Change user's mind: Choice position 2 (NO SUCCESS)
*  If user does not change his mind: Position 1 (SUCCESS)
*  Register this success rate for NUMBER_OF_TRIES times
*
*/
int successIfNotChange=0;
int successIfChange=0;
for (int i=0;i <NUMBER_OF_TRIES; i++){
 def myarray =fillArray(); //get original door array
 int one=getPricePosition(myarray); //get position of the price (1)
 int myGuess= (int) ((Math.random ()*100) % 3); //user choices a position
  //trim door array with two remaining positions, and get the position of the discarded door
 int discarded=getChoicedArray(myarray,myGuess,one);
 if(myarray[myGuess]==1){ //keep original  user choice and see if user was right
    successIfNotChange++;
  }
  //ExChange  user choice  with the alternative remaining door and see if success
 if (myarray[changePos(myGuess,discarded,myarray)]==1){
     successIfChange++; //success counter
  }
}
//Print results, if the algorithm is right shoud be around 33% and 66%
double total= (successIfNotChange/NUMBER_OF_TRIES) *100;
println "Success rate if user do not change his mind  "+total+" %";

double total1= (successIfChange/NUMBER_OF_TRIES) *100;
println "Success rate if user  change his mind "+total1+" %";