564 lines
12 KiB
Java
564 lines
12 KiB
Java
/*This is a Java Program to implement a Singly Linked List. A linked list is a data structure consisting of a group of nodes which together represent a sequence. Under the simplest form, each node is composed of a data and a reference (in other words, a link) to the next node in the sequence. This structure allows for efficient insertion or removal of elements from any position in the sequence. In a singly linked list each node has only one link which points to the next node in the list.*/
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/*
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* Java Program to Implement Singly Linked List
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*/
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import java.util.Scanner;
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/* Class Node */
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class Node
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{
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protected int data;
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protected Node link;
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/* Constructor */
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public Node()
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{
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link = null;
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data = 0;
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}
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/* Constructor */
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public Node(int d,Node n)
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{
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data = d;
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link = n;
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}
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/* Function to set link to next Node */
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public void setLink(Node n)
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{
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link = n;
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}
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/* Function to set data to current Node */
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public void setData(int d)
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{
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data = d;
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}
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/* Function to get link to next node */
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public Node getLink()
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{
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return link;
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}
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/* Function to get data from current Node */
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public int getData()
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{
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return data;
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}
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}
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/* Class linkedList */
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class linkedList
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{
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protected Node start;
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protected Node end ;
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public int size ;
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/* Constructor */
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public linkedList()
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{
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start = null;
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end = null;
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size = 0;
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}
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/* Function to check if list is empty */
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public boolean isEmpty()
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{
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return start == null;
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}
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/* Function to get size of list */
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public int getSize()
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{
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return size;
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}
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/* Function to insert an element at begining */
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public void insertAtStart(int val)
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{
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Node nptr = new Node(val, null);
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size++ ;
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if(start == null)
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{
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start = nptr;
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end = start;
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}
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else
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{
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nptr.setLink(start);
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start = nptr;
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}
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}
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/* Function to insert an element at end */
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public void insertAtEnd(int val)
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{
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Node nptr = new Node(val,null);
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size++ ;
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if(start == null)
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{
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start = nptr;
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end = start;
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}
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else
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{
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end.setLink(nptr);
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end = nptr;
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}
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}
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/* Function to insert an element at position */
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public void insertAtPos(int val, int pos)
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{
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Node nptr = new Node(val, null);
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Node ptr = start;
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pos = pos - 1 ;
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for (int i = 1; i < size; i++)
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{
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if (i == pos)
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{
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Node tmp = ptr.getLink() ;
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ptr.setLink(nptr);
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nptr.setLink(tmp);
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break;
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}
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ptr = ptr.getLink();
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}
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size++ ;
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}
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/* Function to delete an element at position */
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public void deleteAtPos(int pos)
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{
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if (pos == 1)
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{
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start = start.getLink();
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size--;
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return ;
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}
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if (pos == size)
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{
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Node s = start;
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Node t = start;
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while (s != end)
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{
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t = s;
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s = s.getLink();
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}
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end = t;
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end.setLink(null);
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size --;
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return;
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}
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Node ptr = start;
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pos = pos - 1 ;
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for (int i = 1; i < size - 1; i++)
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{
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if (i == pos)
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{
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Node tmp = ptr.getLink();
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tmp = tmp.getLink();
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ptr.setLink(tmp);
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break;
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}
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ptr = ptr.getLink();
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}
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size-- ;
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}
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/* Function to display elements */
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public void display()
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{
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System.out.print("\nSingly Linked List = ");
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if (size == 0)
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{
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System.out.print("empty\n");
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return;
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}
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if (start.getLink() == null)
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{
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System.out.println(start.getData() );
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return;
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}
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Node ptr = start;
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System.out.print(start.getData()+ "->");
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ptr = start.getLink();
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while (ptr.getLink() != null)
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{
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System.out.print(ptr.getData()+ "->");
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ptr = ptr.getLink();
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}
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System.out.print(ptr.getData()+ "\n");
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}
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}
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/* Class SinglyLinkedList */
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public class SinglyLinkedList
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{
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public static void main(String[] args)
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{
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Scanner scan = new Scanner(System.in);
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/* Creating object of class linkedList */
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linkedList list = new linkedList();
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System.out.println("Singly Linked List Test\n");
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char ch;
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/* Perform list operations */
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do
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{
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System.out.println("\nSingly Linked List Operations\n");
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System.out.println("1. insert at begining");
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System.out.println("2. insert at end");
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System.out.println("3. insert at position");
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System.out.println("4. delete at position");
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System.out.println("5. check empty");
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System.out.println("6. get size");
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int choice = scan.nextInt();
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switch (choice)
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{
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case 1 :
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System.out.println("Enter integer element to insert");
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list.insertAtStart( scan.nextInt() );
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break;
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case 2 :
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System.out.println("Enter integer element to insert");
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list.insertAtEnd( scan.nextInt() );
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break;
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case 3 :
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System.out.println("Enter integer element to insert");
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int num = scan.nextInt() ;
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System.out.println("Enter position");
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int pos = scan.nextInt() ;
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if (pos <= 1 || pos > list.getSize() )
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System.out.println("Invalid position\n");
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else
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list.insertAtPos(num, pos);
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break;
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case 4 :
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System.out.println("Enter position");
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int p = scan.nextInt() ;
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if (p < 1 || p > list.getSize() )
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System.out.println("Invalid position\n");
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else
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list.deleteAtPos(p);
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break;
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case 5 :
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System.out.println("Empty status = "+ list.isEmpty());
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break;
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case 6 :
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System.out.println("Size = "+ list.getSize() +" \n");
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break;
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default :
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System.out.println("Wrong Entry \n ");
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break;
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}
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/* Display List */
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list.display();
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System.out.println("\nDo you want to continue (Type y or n) \n");
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ch = scan.next().charAt(0);
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}
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while (ch == 'Y'|| ch == 'y');
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}
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}
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/*
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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5
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Empty status = true
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Singly Linked List = empty
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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1
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Enter integer element to insert
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5
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Singly Linked List = 5
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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1
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Enter integer element to insert
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7
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Singly Linked List = 7->5
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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2
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Enter integer element to insert
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4
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Singly Linked List = 7->5->4
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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2
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Enter integer element to insert
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2
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Singly Linked List = 7->5->4->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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1
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Enter integer element to insert
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9
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Singly Linked List = 9->7->5->4->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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3
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Enter integer element to insert
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3
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Enter position
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3
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Singly Linked List = 9->7->3->5->4->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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3
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Enter integer element to insert
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2
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Enter position
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2
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Singly Linked List = 9->2->7->3->5->4->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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6
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Size = 7
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Singly Linked List = 9->2->7->3->5->4->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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4
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Enter position
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4
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Singly Linked List = 9->2->7->5->4->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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4
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Enter position
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2
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Singly Linked List = 9->7->5->4->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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4
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Enter position
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1
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Singly Linked List = 7->5->4->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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4
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Enter position
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3
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Singly Linked List = 7->5->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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4
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Enter position
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1
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Singly Linked List = 5->2
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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4
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Enter position
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2
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Singly Linked List = 5
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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4
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Enter position
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1
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Singly Linked List = empty
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Do you want to continue (Type y or n)
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y
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Singly Linked List Operations
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1. insert at begining
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2. insert at end
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3. insert at position
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4. delete at position
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5. check empty
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6. get size
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5
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Empty status = true
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Singly Linked List = empty
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Do you want to continue (Type y or n)
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n
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