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Thread: Lists of Sets and Sets of Lists

  1. #1
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    Default Lists of Sets and Sets of Lists

    Write a program that reads several lines of integers. Each line of integers should be stored in
    an object of type List<Integer>, and all the lines should be stored in an object of type
    HashSet<List<Integer>>. Then the program should print out the contents of this set.


    import java.util.*;
     
    class q2
    {
     public static void main(String[] args) throws Exception
     {
      String morelines = "Yes";
      int j=0;
      while (!morelines.equals("No")) {
      Scanner input = new Scanner(System.in);
      System.out.println("Enter some integers (all on one line):");
      String linej = input.nextLine();
      String[] numsj = linej.split(" ");
     
      List<Integer> aj = new HashSet<List<Integer>>();
      for(int i=0; i<numsj.length; i++)
         aj.add(Integer.parseInt(numsj[i]));
     
      System.out.println("Do you want to enter some more lines? Yes or No");
      morelines = input.nextLine();
     
      j=j+1;
      }
      for (int i=0; i<j; i++)
      System.out.println("The integers are: "+ai);
     }
    }

    Whats wrong with the code?
    Last edited by Freaky Chris; December 8th, 2009 at 08:09 PM.


  2. #2
    Administrator copeg's Avatar
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    Default Re: Lists of Sets and Sets of Lists

    You cannot assign a HashSet to a List

    List<Integer> aj = new HashSet<List<Integer>>();//???

    It'd be more appropriate to create a new list for each line, add things, then add the list to a previously created HashSet

  3. #3
    Senile Half-Wit Freaky Chris's Avatar
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    Default Re: Lists of Sets and Sets of Lists

    HashSet< List<Integer> > aj = new HashSet<List<Integer>>();

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