Assignment No:1

 //Assignment No:1

Set A 

a) Write a java program to accept names of ‘n’ cities, insert same into array list collection and display the contents of same array list, also remove all these elements.

CODE

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1. import java.util.*;
2. public class city
3. {
4. public static void main(String args[])
5. {
6. Scanner sc = new Scanner(System.in);
7. ArrayList<String> al = new  ArrayList<String>();
8. String c;
9. System.out.println("How Many City..?");
10. int n = sc.nextInt();
11. for(int i=0; i<n; i++)
12. {
13. System.out.println("Enter City Name");
14. c = sc.next();
15. al.add(c);
16. }
17. System.out.println("Citys are"+al);
18. al.clear();
19. if(al.isEmpty() == true)
20. System.out.println("Arraylist is empty");
21. else
22. System.out.println("Arraylist is not empty");
23. }
24. }

b) Write a java program to read ‘n’ names of your friends, store it into linked list, also display contents of the same.

CODE

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1. import java.util.*;
2. public class friends
3. {
4. public static void main(String args[])
5. {
6. Scanner sc = new Scanner(System.in);
7. LinkedList<String> ll = new  LinkedList<String>();
8. String c;
9. System.out.println("How Many Friends.?");
10. int n = sc.nextInt();
11. for(int i=0; i<n; i++)
12. {
13. System.out.println("Enter Friends Name");
14. c = sc.next();
15. ll.add(c);
16. }
17. System.out.println("Friends are"+ll);
18. }
19. }

c) Write a program to create a new tree set, add some colors (string) and print out the tree set.

CODE

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1. import java.util.*;
2. public class colors
3. {
4. public static void main(String args [])
5. {
6. Scanner sc = new Scanner(System.in);
7. TreeSet<String> ts = new TreeSet<String>();
8. System.out.println("How many Colors..?");
9. int n = sc.nextInt();
10. for(int i=1; i <=n; i++)
11. {
12. System.out.println("Enter Color "+i);
13. String c = sc.next();
14. ts.add(c);
15. }
16. //System.out.println("Colors are"+ts);
17. Iterator itr = ts.iterator();
18. while(itr.hasNext())
19. {
20. System.out.println("Colors Are : "+itr.next());
21. }
22. }
23. }

d) Create the hash table that will maintain the mobile number and student name. Display the contact list.

CODE

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1. import java.io.*;
2. import java.util.*;
3. class hash_table
4. {
5. public static void main (String args[]) throws Exception
6. {
7. Hashtable<String,Integer> ht = new Hashtable<String,Integer>();
8. Scanner sc = new Scanner(System.in);
9. int mno;
10. String name = null;
11. System.out.println("\nEnter no of Students");
12. int n = sc.nextInt();
13. for(int i=0; i<n; i++)
14. {
15. System.out.println("Enter Student Name:");
16. name = sc.next();
17. System.out.println("Enter Student Mobile No:");
18. mno = sc.nextInt();
19. ht.put(name,mno);
20. }
21. System.out.println("Hash Table"+ht);
22. Enumeration k = ht.keys();
23. Enumeration v = ht.elements();
24. System.out.println("Name\tMobile Numbers");
25. while(k.hasMoreElements())
26. {
27. System.out.println(k.nextElement()+"\t"+k.nextElement());
28. }
29. }
30. }

Set B

 a) Accept ‘n’ integers from the user. Store and display integers in sorted order having proper collection class. The collection should not accept duplicate elements.

CODE

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1. import java.util.*;
2. public class treeset
3. {
4. public static void main(String args [])
5. {
6. Scanner sc = new Scanner(System.in);
7. TreeSet<Integer> ts = new TreeSet<Integer>();
8. System.out.println("How many Numbers");
9. int n = sc.nextInt();
10. for(int i=1; i <=n; i++)
11. {
12. System.out.println("Enter Number "+i);
13. int num = sc.nextInt();
14. ts.add(num);
15. }
16. System.out.println("The Sorted Numbers are"+ts);
17. }
18. }

b) Write a program to sort HashMap by keys and display the details before sorting and after sorting.

CODE

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1. import  java.util.*;
2. public class SortHashMap
3. {
4. public static void main(String args [])
5. {
6. Scanner sc = new Scanner(System.in);
7. HashMap<Integer, String> hm = new HashMap<Integer, String>();
8. System.out.println("How many Students");
9. int n = sc.nextInt();
10. for(int i=1; i <=n; i++)
11. {
12. System.out.println("Enter Roll No "+i+" Student");
13. int num = sc.nextInt();
14. System.out.println("Enter Name "+i+" Stdudent");
15. String name = sc.next();
16. hm.put(num,name);
17. }
18. Iterator <Integer> it = hm.keySet().iterator();
19. System.out.println("Before Sorting");
20. while(it.hasNext())
21. {
22. int key = (int)it.next();
23. System.out.println("Rol No: "+key+"Name "+hm.get(key));
24. }
25. System.out.println("\nAfter Sorting");
26. TreeMap <Integer,String> tm = new TreeMap <Integer,String> (hm);
27. Iterator <Integer> itr = tm.keySet().iterator();
28. while(itr.hasNext())
29. {
30. int key = (int)itr.next();
31. System.out.println("Roll No: "+key+" Name "+hm.get(key));
32. }
33. }
34. }

c) Write a program that loads names and phone numbers from a text file where the data is organized as one line per record and each field in a record are separated by a tab (\t).it takes a name or phone number as input and prints the corresponding other value from the hash table (hint: use hash tables).

CODE

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1. import java.io.*;
2. import java.util.*;
3. public class Phonebook
4. {
5. public static void main(String[] args)
6. {
7. try
8. {
9. FileInputStream fis = new FileInputStream("myfile.txt");
10. Scanner sc = new Scanner(fis).useDelimiter("\t");
11. Hashtable<String, String> ht = new Hashtable<String, String> ();
12. String[] strarray;
13. String a, str;
14. while(sc.hasNext())
15. {
16. a = sc.nextLine();
17. strarray = a.split("\t");
18. ht.put(strarray[0],strarray[1]);
19. System.out.println("Hash Table Values "+strarray[0]+":"+strarray[1]);
20. }
21. Scanner s = new Scanner(System.in);
22. System.out.println("Enter the name as given in the phone book");
23. str = s.nextLine();
24. if(ht.containsKey(str))
25. {
26. System.out.println("Phone no is "+ht.get(str));
27. }
28. else
29. {
30. System.out.println("Name is not matched");
31. }
32. }
33. catch(Exception e)
34. {
35. System.out.println(e);
36. }
37. }
38. }