研究去除重複的元素

Question

的

可能重複：
Removing duplicates from the list with different ways

我是做了研究，並找到這下面的方法來從list..but刪除重複的請指教是還有其他的方法，因爲我正在研究這個問題，我想在集合中探索其他方法，這將是一個很好的例子。我對我的研究更感興趣的是新的jdk 1.5有一些新東西提供這個背景

class Emp //implements Comparable 
{ 
     String name,job; 
     int salary; 
     public Emp(String n,String j,int sal) 
     { 
     name=n; 
     job=j; 
     salary=sal; 
     } 
     public void display() 
     { 
     System.out.println(name+"\t"+job+"\t"+salary); 
     } 
    public boolean equals(Object o) 
     { 

     Emp p=(Emp)o; 
      return this.name.equals(p.name)&&this.job.equals(p.job) &&this.salary==p.salary; 
     } 
    public int hashCode() 
     { 
      return name.hashCode()+job.hashCode()+salary; 
     } 


     /* public int compareTo(Object o) 
     { 
      Emp e=(Emp)o; 
      return this.name.compareTo(e.name); 
      //return this.job.compareTo(e.job); 
     // return this.salary-e.salary; 

     }*/ 
} 

和最後一類將...

class EmpListDemo 
    { 
      public static void main(String arg[]) 
      { 
       List list=new ArrayList(); 
       list.add(new Emp("Ram","Trainer",34000)); 
       list.add(new Emp("Sachin","Programmer",24000)); 
       list.add(new Emp("Ram","Trainer",34000)); 
       list.add(new Emp("Priyanka","Manager",54000)); 
       list.add(1,new Emp("Ravi","Administrator",44000)); 
       list.add(new Emp("Anupam","Programmer",34000)); 
       list.add(new Emp("Priyanka","Manager",54000)); 
       list.add(new Emp("Sachin","Team Leader",54000)); 
       System.out.println("There are "+list.size()+" elements in the list."); 



       System.out.println("Content of list are : "); 
       ListIterator itr1=list.listIterator(); 
       while(itr1.hasNext()) 
       { 
       Emp e=(Emp)itr1.next(); 
       e.display(); 
       }   

//Removing duplicates from the list 
      Set hs = new HashSet(); 
      hs.addAll(list); 
      list.clear(); 
      list.addAll(hs); 
      System.out.println("******************************"); 
      System.out.println("There are "+hs.size()+" elements in the set."); 
      System.out.println("Contents after modification : "); 
      Iterator itr=list.iterator(); 
      while(itr.hasNext()) 
      { 
      Emp e=(Emp)itr.next(); 
      e.display(); 
      } 




       } 
    } 

Answer 1

使用HashSet：

class EmpListDemo 
{ 
    public static void main(String arg[]) 
    { 
     Set list = new HashSet(); 
     list.add(new Emp("Ram","Trainer",34000)); 
     list.add(new Emp("Sachin","Programmer",24000)); 
     list.add(new Emp("Ram","Trainer",34000)); 
     list.add(new Emp("Priyanka","Manager",54000)); 
     list.add(new Emp("Ravi","Administrator",44000)); 
     list.add(new Emp("Anupam","Programmer",34000)); 
     list.add(new Emp("Priyanka","Manager",54000)); 
     list.add(new Emp("Sachin","Team Leader",54000)); 
     System.out.println("There are "+list.size()+" elements in the list."); 



     System.out.println("Content of list are : "); 
     ListIterator itr1=list.listIterator(); 
     while(itr1.hasNext()) 
     { 
     Emp e=(Emp)itr1.next(); 
     e.display(); 
     }   

     } 
} 

Answer 2

使用Set兄弟的任何實施.. 而不是讓重複再後來刪除它; 甚至不允許他們的數據結構...