java - Compact a list based on a value -

having simple class such as:

public class label {     public string id;     public double amount; } 

and having list following values (list sorted in amount ascending order):

id        amount ---------------- 1742      10 1742      11 1647      12 4217      13 1647      14 1742      15 

is there simple way compact list lowest amount id remains. so, after compaction, list should this:

id        amount ---------------- 1742      10 1647      12 4217      13 

here 1 way of doing it. method makeunique() keep labels have minimum amounts.

public class label {     public string id;     public double amount;      public label(string id, double amount) {         super();         this.id = id;         this.amount = amount;     }      public static map<string, label> makeunique(list<label> list) {         map<string, label> map = new hashmap<string, label>();          (label label : list) {             if(!map.containskey(label.id)) map.put(label.id, label);         }         return map;     }      public static void main(string[] args) {         list<label> list = new arraylist<label>();         list.add(new label("1742", 10));         list.add(new label("1742", 11));         list.add(new label("1647", 12));         list.add(new label("1647", 14));         map<string, label> map = makeunique(list);     }  }