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This time Queues with Linked Lists

Same as the earlier posts Here's the implementation.

 Node Class


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public class NodeClass {
    public int info; 
    public NodeClass next; 
    public NodeClass(int i){    
        this(i,null);
    }
    public NodeClass(int x, NodeClass n){
        info = x;
        next = n;
    }

}


The implementation:


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public class QueueWithLL {
    protected NodeClass head, tail;

    public QueueWithLL() {
        head = tail = null;
    }
    public boolean isEmpty(){
        return(head == null && tail == null);
    }
    public void add(int x){
        if(isEmpty()){
            head = tail = new NodeClass(x);
        }else{
            tail.next = new NodeClass(x, null);
            tail = tail.next;
        }
    }
    public int peekFront(){
        return head.info;
    }
    public int peekRear(){
        return tail.info;
    }
    public int pop(){
        int temp = head.info;
        head = head.next;
        return temp;
    }
    public static void main(String[] args) {
        QueueWithLL queue = new QueueWithLL();
        queue.add(34);
        queue.add(45);
        queue.add(78);
        queue.add(100);
        System.out.println("Head peek :"+queue.peekFront());
        System.out.println("Rear peek :"+queue.peekRear());        
        System.out.println("Pop the head element :"+queue.pop());
        System.out.println("Pop the next head element :"+queue.pop());
    }
    
}

Have fun.
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Location: Sri Jayawardenepura Kotte, Sri Lanka

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