None LC_Note

https://lizhouchi.gitbooks.io/algorithms-solution/content/chapter2/remove_duplicate_numbers_in_array.html

PriorityQueue smallest number come out first..(natural order)

PriorityQueue<Point> pq = new PriorityQueue<Point>(k,new Comparator<Point>(){
          public int compare(Point a,Point b){
          return (int) (getDistance(b,origin)- getDistance(a,origin));
          }
     });