AlgoExpert Class Photos

import java.util.*;

class Program {

  public boolean classPhotos(
      ArrayList<Integer> redShirtHeights, ArrayList<Integer> blueShirtHeights) {
    Collections.sort(redShirtHeights);
    Collections.sort(blueShirtHeights);
    int diff = redShirtHeights.get(0) - blueShirtHeights.get(0);
    for (int i = 0; i < redShirtHeights.size(); i++){
      if ((redShirtHeights.get(i) - blueShirtHeights.get(i))*diff <= 0){
        return false;
      } 
    }
    return true;
  }
}