1) poll, pollFirst, pollLast : display plus remove
import java.util.LinkedList;
public class LinkedListExample {
public static void main(String[] args) {
LinkedList<Integer> linkedList = new LinkedList<Integer>();
linkedList.add(23);
linkedList.add(24);
linkedList.add(25);
linkedList.add(28);
linkedList.add(29);
System.out.println("Linked list before poll() ");
System.out.println(linkedList);
linkedList.poll();
System.out.println("Linked list after poll() ");
System.out.println(linkedList);
System.out.println("Linked list before pollFirst() ");
System.out.println(linkedList);
linkedList.pollFirst();
System.out.println("Linked list after pollFirst() ");
System.out.println(linkedList);
System.out.println("Linked list before pollLast() ");
System.out.println(linkedList);
linkedList.pollLast();
System.out.println("Linked list after pollLast() ");
System.out.println(linkedList);
}
}
Linked list before poll()
[23, 24, 25, 28, 29]
Linked list after poll()
[24, 25, 28, 29]
Linked list before pollFirst()
[24, 25, 28, 29]
Linked list after pollFirst()
[25, 28, 29]
Linked list before pollLast()
[25, 28, 29]
Linked list after pollLast()
[25, 28]
Example 2: (Queue using LinkedList)
import java.util.LinkedList;
public class PlayersLLExample {
public static void main(String[] args) {
LinkedList<String> players = new LinkedList<String>();
players.add("Akash");
players.add("Shivam");
players.add("Mohit");
players.add("Rahul");
while (!players.isEmpty()) {
System.out.print(" Player exited " + players.poll() + "<-- ");
}
}
}
Player exited Akash<-- Player exited Shivam<-- Player exited Mohit<-- Player exited Rahul<--
import java.util.LinkedList;
public class LinkedListExample {
public static void main(String[] args) {
LinkedList<Integer> linkedList = new LinkedList<Integer>();
linkedList.add(23);
linkedList.add(24);
linkedList.add(25);
linkedList.add(28);
linkedList.add(29);
System.out.println("Linked list before peek() ");
System.out.println(linkedList);
System.out.println("element peeked " + linkedList.peek());
System.out.println("Linked list after peek() ");
System.out.println(linkedList);
System.out.println("Linked list before peekFirst() ");
System.out.println(linkedList);
System.out.println("element peeked " + linkedList.peekFirst());
System.out.println("Linked list after peekFirst() ");
System.out.println(linkedList);
System.out.println("Linked list before peekLast() ");
System.out.println(linkedList);
System.out.println("element peeked " + linkedList.peekLast());
System.out.println("Linked list after peekLast() ");
System.out.println(linkedList);
}
}
Linked list before peek()
[23, 24, 25, 28, 29]
element peeked 23
Linked list after peek()
[23, 24, 25, 28, 29]
Linked list before peekFirst()
[23, 24, 25, 28, 29]
element peeked 23
Linked list after peekFirst()
[23, 24, 25, 28, 29]
Linked list before peekLast()
[23, 24, 25, 28, 29]
element peeked 29
Linked list after peekLast()
[23, 24, 25, 28, 29]
3) offer, offerFirst, offerLast : to add element at first or last
import java.util.LinkedList;
public class LinkedListExampleOp2 {
public static void main(String[] args) {
LinkedList<Integer> linkedList = new LinkedList<Integer>();
linkedList.add(23);
linkedList.add(24);
linkedList.add(25);
linkedList.add(28);
linkedList.add(29);
System.out.println("Linked list before offer(someInt) ");
System.out.println(linkedList);
System.out.println("element offered " + linkedList.offer(30));
System.out.println("Linked list after offer(someInt) ");
System.out.println(linkedList);
System.out.println("Linked list before offerFirst(someInt) ");
System.out.println(linkedList);
System.out.println("element offered " + linkedList.offerFirst(31));
System.out.println("Linked list after offerFirst(someInt) ");
System.out.println(linkedList);
System.out.println("Linked list before offerLast(someInt) ");
System.out.println(linkedList);
System.out.println("element offered " + linkedList.offerLast(32));
System.out.println("Linked list after offerLast(someInt) ");
System.out.println(linkedList);
}
}
Linked list before offer(someInt)
[23, 24, 25, 28, 29]
element offered true
Linked list after offer(someInt)
[23, 24, 25, 28, 29, 30]
Linked list before offerFirst(someInt)
[23, 24, 25, 28, 29, 30]
element offered true
Linked list after offerFirst(someInt)
[31, 23, 24, 25, 28, 29, 30]
Linked list before offerLast(someInt)
[31, 23, 24, 25, 28, 29, 30]
element offered true
Linked list after offerLast(someInt)
[31, 23, 24, 25, 28, 29, 30, 32]
4) indexOf , lastIndexOf :
import java.util.LinkedList;
public class LinkedListIndexOfEx {
public static void main(String[] args) {
LinkedList<Integer> linkedList = new LinkedList<Integer>();
linkedList.add(23); // 0
linkedList.add(24); // 1
linkedList.add(25); // 2 -- first index of 25
linkedList.add(28); // 3
linkedList.add(25); // 4
linkedList.add(29); // 5
linkedList.add(25); // 6 -- last index of 25
linkedList.add(31); // 7
int index = linkedList.indexOf(25);
System.out.println("first occurence index of 25 is " + index);
index = linkedList.lastIndexOf(25);
System.out.println("last occurence index of 25 is " + index);
}
}
first occurence index of 25 is 2
last occurence index of 25 is 6
Problems:
1. Write a Java program to append the specified element to the end of a linked list.
2. Write a Java program to iterate through all elements in a linked list.
3. Write a Java program to iterate through all elements in a linked list starting at the specified position.
4. Write a Java program to iterate a linked list in reverse order.
5. Write a Java program to insert the specified element at the specified position in the linked list.
6. Write a Java program to insert elements into the linked list at the first and last position.
7. Write a Java program to insert the specified element at the front of a linked list.
8. Write a Java program to insert the specified element at the end of a linked list.
9. Write a Java program to insert some elements at the specified position into a linked list.
10. Write a Java program to get the first and last occurrence of the specified elements in a linked list.
11. Write a Java program to display the elements and their positions in a linked list.
12. Write a Java program to remove a specified element from a linked list.
13. Write a Java program to remove first and last element from a linked list.
14. Write a Java program to remove all the elements from a linked list.
15. Write a Java program of swap two elements in an linked list.
16. Write a Java program to shuffle the elements in a linked list.
17. Write a Java program to join two linked lists.
18. Write a Java program to clone an linked list to another linked list.
19. Write a Java program to remove and return the first element of a linked list.
20. Write a Java program to retrieve but does not remove, the first element of a linked list.
21. Write a Java program to retrieve but does not remove, the last element of a linked list.
22. Write a Java program to check if a particular element exists in a linked list.
23. Write a Java program to convert a linked list to array list.
24. Write a Java program to compare two linked lists.
25. Write a Java program to test an linked list is empty or not.
26. Write a Java program to replace an element in a linked list.
