Chances of neighbouring sits

import java.util.Vector;

int[] spots;
int favourableCases;
int totalCases;
int NUMBER_OF_PEOPLE = 7;
int CYCLES_PER_FRAME = 1000;

void setup() {

  frameRate(60);

  size(600,180);

  spots = new int[NUMBER_OF_PEOPLE];

  for (int i = 0; i < NUMBER_OF_PEOPLE; i++) {

    spots[i] = i+1;

  }

}

void draw() {

  background(255);

  for (int i = 0; i < CYCLES_PER_FRAME; i++) {

    totalCases++;

    shufflePeople();

    checkNeightbour();

  }

  fill(0, 0, 0);
  noFill();
  rect(30, 30, 50 * NUMBER_OF_PEOPLE, 50);
  for (int j = 0; j < NUMBER_OF_PEOPLE; j++) {

    line(30 + 50*j, 30, 30 + 50*j, 80);

  }
  ellipseMode(CORNER);
  fill(0, 255, 0);
  pushMatrix();
  translate(30 + (50 * positionOf(1)), 30);
  ellipse(0, 0, 50, 50);
  popMatrix();
  fill(255, 0, 0);
  pushMatrix();
  translate(30 + (50 * positionOf(2)), 30);
  ellipse(0, 0, 50, 50);
  popMatrix();

  fill(0);
  text("Favourable cases: " + favourableCases, 30, 100);
  text("Total cases: " + totalCases, 30, 115);
  text("Chance: " + (100 * ((double)favourableCases/(double)totalCases)) + "%", 30, 130);
  text("Expected Chance: " + (10.0/36.0)*100 + "%", 300, 100);
}

public int positionOf(int n) {

  int position = 0;

  for (int i = 0; i < NUMBER_OF_PEOPLE; i++) {

    if (spots[i] == n) {
      position = i;
    }

  }

  return position;

}

public void checkNeightbour() {

  if (spots[0] == 1 && spots[1] == 2) {
    favourableCases++;
  } else if (spots[NUMBER_OF_PEOPLE - 1] == 1 && spots[NUMBER_OF_PEOPLE - 2] == 2) {
    favourableCases++;
  } else {
    for (int i = 1; i < NUMBER_OF_PEOPLE - 1; i++) {
      if ((spots[i] == 1 && spots[i + 1] == 2) || (spots[i] == 1 && spots[i - 1] == 2)) {
        favourableCases++;
      }
    }
  }

}

public void shufflePeople() {

  Vector<Integer> aviablePeople = new Vector<Integer>();

  for (int i = 0; i < NUMBER_OF_PEOPLE; i++) {

    aviablePeople.add(spots[i]);

  }

  for (int i = 0; i < NUMBER_OF_PEOPLE; i++) {

    int randPosition = (int)(Math.random() * aviablePeople.size());
    spots[i] = aviablePeople.get(randPosition);
    aviablePeople.remove(randPosition);

  }

}