X Tutup
package DataStructures.Stacks; /** * @author Varun Upadhyay (https://github.com/varunu28) */ // An implementation of a Stack using a Linked List class StackOfLinkedList { public static void main(String[] args) { LinkedListStack stack = new LinkedListStack(); stack.push(1); stack.push(2); stack.push(3); stack.push(4); stack.push(5); stack.printStack(); System.out.println("Size of stack currently is: " + stack.getSize()); stack.pop(); stack.pop(); System.out.println("Top element of stack currently is: " + stack.peek()); } } // A node class class Node { public int data; public Node next; public Node(int data) { this.data = data; this.next = null; } } /** * A class which implements a stack using a linked list *

* Contains all the stack methods : push, pop, printStack, isEmpty **/ class LinkedListStack { Node head = null; public void push(int x) { Node n = new Node(x); if (head == null) { head = n; } else { Node temp = head; n.next = temp; head = n; } } public void pop() { if (head == null) { System.out.println("Empty stack. Nothing to pop"); } Node temp = head; head = head.next; System.out.println("Popped element is: " + temp.data); } public int peek() { if (head == null) { return -1; } return head.data; } public void printStack() { Node temp = head; System.out.println("Stack is printed as below: "); while (temp != null) { if (temp.next == null) { System.out.print(temp.data); } else { System.out.print(temp.data + " -> "); } temp = temp.next; } System.out.println(); } public boolean isEmpty() { return head == null; } public int getSize() { if (head == null) return 0; else { int size = 1; Node temp = head; while (temp.next != null) { temp = temp.next; size++; } return size; } } }

X Tutup