IterativeSearchLinkedList.java

/*
 *               Search (iterative)
 * 
 *     Search for a key in a linked list return the position where it is found .
 *     if not found , return-1.
 */

public class IterativeSearchLinkedList {

    // Search Linked List
    public static int itrSearchLL(int key){
        int position=0;
        Node temp=head;
        while(temp!=null){
            if(temp.data==key){
                return position;
            }
            temp=temp.next;
            position++;
        }
        return -1;
    }

   

    public static void main(String[] args) {
        IterativeSearchLinkedList ll = new IterativeSearchLinkedList();

        ll.addFirst(5);
        ll.addFirst(4);
        ll.addFirst(3);
        ll.addFirst(2);
        ll.addMid(2,10);
        ll.addLast(6);
        ll.addLast(7);
        ll.addMid(0, 50);
        printLL();
        System.out.println("\nSize of LinkedList : " + ll.size);
        removeFirst();
        printLL();
        System.out.println("\nSize of LinkedList : " + ll.size);
        removeLast();
        printLL();
        System.out.println("\nSize of LinkedList : " + ll.size);
        System.out.println("Position: " + itrSearchLL(4));
    }

    public static class Node{
        int data;
        Node next;
        Node(int data){
            this.data = data;
            this.next = null;
        }
    }

    public static Node head;
    public static Node tail;
    public static int size=0;

    // Remove in first
    public static int removeFirst(){
        if (size==0) {
            System.out.println("Linked List is Empty");
            return Integer.MIN_VALUE;
        }
        if(size==1){
            int data = head.data;
            head = tail = null;
            size=0;
            return data;
        }

        int data = head.data;
        head = head.next;
        size--;
        return data;
    }

    // remove Last
    public static int removeLast(){
        
        if (size==0) {
            System.out.println("Linked List is Empty");
            return Integer.MIN_VALUE;
        }
        
        if(size==1){
            int data = tail.data;
            head = tail = null;
            size=0;
            return data;
        }
        
        Node prev = head;
        for(int i=0; i<size-2; i++){
            prev = prev.next;
        }

        int data = tail.data;
        prev.next= null;
        tail = prev;
        size--;
        return data;
    }

    // Add in middles
    public void addMid(int index, int data){
        if (index==0) {
        addFirst(data);
        return;
        }
        Node nextNode = new Node(data);
        size++;
        Node temp = head;
        int  i=0;
        while (i<index-1) {
            temp=temp.next;
            i++;
        }
        nextNode.next=temp.next;
        temp.next = nextNode;
    }   

    // add First
    public void addFirst(int data){
        Node nextNode = new Node(data);
        size++;
        if(head==null){
            head=tail=nextNode;
            return;
        }
        nextNode.next= head;
        head=nextNode;
    }

    // add Last
    public void addLast(int data){
        Node nextNode = new Node(data);
        size++;
        if(head==null){
            head=tail=nextNode;
            return;
        }
        tail.next= nextNode;
        tail=nextNode;
    }

    // Print Linked List
    public static void printLL(){
        if (head==null) {
            System.out.println("LinkedList is a Emtey");
            return;
        }
    
        Node temp = head;
        while (temp!=null) {
            System.out.print(temp.data+ " ");
            temp = temp.next;
        }
    }      
}

/*
 *   Output
 *   50 2 3 10 4 5 6 7 
 *   Size of LinkedList : 8
 *   2 3 10 4 5 6 7
 *   Size of LinkedList : 7
 *   2 3 10 4 5 6
 *   Size of LinkedList : 6
 *   Position: 3
 */