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Merge pull request #32 from KunwarVikas/master

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Data Structures and Algorithm
This commit is contained in:
javadevjournal
2021-03-08 22:26:11 -08:00
committed by GitHub
parent 3409a03e35 ae8b6fa61b
commit b4a08a35e8
2 changed files with 258 additions and 0 deletions
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183
Java/data-structure-with-java/linkedList/singly/MySinglyLinkedList.java Normal file
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package linkedList.singly;
public class MySinglyLinkedList {
/**
* Head of the LinkedList
*/
public Node head;
/**
* This is a method static class defining a LinkedList Node.
* since it is static, main() method can access it
*/
public static class Node {
public int data;
public Node next;
Node(int data)
{
this.data = data;
next = null;
}
}
/**
* Insert a node to the given LinkedList
* This method will insert at head if the list is empty
* Or else, it will inset at last
* @param list - LinkedList
* @param data - node data
*/
public static void insert(MySinglyLinkedList list, int data)
{
Node node = new Node(data);
node.next = null;
// If the LinkedList is empty, then make the new node as head.
if (list.head == null) {
list.head = node;
}
else {// else traverse the list till the last node and insert at the last.
Node last = list.head;
while (last.next != null) {
last = last.next;
}
// Insert the new node at last node
last.next = node;
}
}
/**
* This method will insert the new node after any given node.
* @param previousNode
* @param dataToBeInserted
*/
public void insertAfter(Node previousNode, int dataToBeInserted)
{
if (previousNode == null)
{
System.out.println("The given previous node cannot be null");
return;
}
Node newNode = new Node(dataToBeInserted);
newNode.next = previousNode.next;
previousNode.next = newNode;
}
/**
* Delete a node by given data at the node.
* @param list - LinkedList
* @param data - node data
*/
public void deleteByKey(MySinglyLinkedList list, int data)
{
System.out.println("trying to delete node with data:" + data);
// Store head node
Node currentNode = list.head;
Node prev = null;
if(currentNode!=null){
if(currentNode.data==data){
list.head = currentNode.next; // Changed head
System.out.println("element " + data + " has been deleted");
}else{
while (currentNode != null && currentNode.data != data) {
prev = currentNode;
currentNode = currentNode.next;
}
if (currentNode != null) {
prev.next = currentNode.next;
System.out.println("element " + data + " has been deleted");
}else{
System.out.println("no node found with data:" + data);
}
}
}
}
/**
* Delete a node by given position.
* @param list - LinkedList
* @param pos - position of the node
*/
public void deleteAtPosition(MySinglyLinkedList list, int pos)
{
System.out.println("trying to delete node at position:"+ pos);
Node currentNode = list.head;
Node prev = null;
int counter = 0;
if(currentNode!=null){
if(pos==0){
list.head = currentNode.next;
System.out.println("element at position" + pos + " has been deleted");
}else{
// Count for the pos to be deleted, keep track of the previous node as it is needed to change currentNode.next
while (currentNode != null) {
if (counter == pos) {
prev.next = currentNode.next;
System.out.println("element at " + pos + " has been deleted");
break;
} else {
prev = currentNode;
currentNode = currentNode.next;
counter++;
}
}
}
}
if(pos>counter){
System.out.println("no node found at position:"+ pos + " ,as it greater than the size of the list");
}
}
/**
* Recursive Searching
* find a node with given data in the LinkedList
* @param head - head node
* @param data - node data
* @return - boolean value (true/false)
*/
public boolean search(Node head, int data)
{
if (head == null)
return false;
if (head.data == data)
return true;
return search(head.next, data);
}
/**
* Traverse and print the list
* @param list
*/
public void traverseAndPrintList(MySinglyLinkedList list)
{
Node currNode = list.head;
System.out.print("LinkedList: ");
while (currNode != null) {
System.out.print(currNode.data + " ");
currNode = currNode.next;
}
System.out.println();
}
/**
*
* @param list
* @return the size of the list
*/
public int size(MySinglyLinkedList list){
int count=0;
Node currNode = list.head;
while (currNode != null) {
count++;
currNode = currNode.next;
}
return count;
}
}

75
Java/data-structure-with-java/linkedList/singly/test/MySinglyLinkedListTest.java Normal file
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package linkedList.singly.test;
import linkedList.singly.MySinglyLinkedList;
import org.junit.Test;
public class MySinglyLinkedListTest {
@Test
public void testLinkedList(){
MySinglyLinkedList list = new MySinglyLinkedList();
//insertion
MySinglyLinkedList.insert(list, 1);
MySinglyLinkedList.insert(list, 2);
MySinglyLinkedList.insert(list, 3);
MySinglyLinkedList.insert(list, 4);
MySinglyLinkedList.insert(list, 5);
MySinglyLinkedList.insert(list, 6);
MySinglyLinkedList.insert(list, 7);
MySinglyLinkedList.insert(list, 8);
MySinglyLinkedList.insert(list, 9);
MySinglyLinkedList.insert(list, 10);
MySinglyLinkedList.insert(list, 11);
MySinglyLinkedList.insert(list, 12);
MySinglyLinkedList.insert(list, 13);
MySinglyLinkedList.insert(list, 14);
MySinglyLinkedList.insert(list, 15);
MySinglyLinkedList.insert(list, 16);
//size of the list
System.out.println("size of the list at the beginning: " + list.size(list));
//delete by key
list.traverseAndPrintList(list);
list.deleteByKey(list, 1);
list.traverseAndPrintList(list);
list.deleteByKey(list, 4);
list.traverseAndPrintList(list);
list.deleteByKey(list, 10);
list.traverseAndPrintList(list);
list.deleteByKey(list, 17);
list.traverseAndPrintList(list);
//delete by position
list.deleteAtPosition(list, 0);
list.traverseAndPrintList(list);
list.deleteAtPosition(list, 2);
list.traverseAndPrintList(list);
list.deleteAtPosition(list, 10);
list.traverseAndPrintList(list);
list.deleteAtPosition(list, 18);
list.traverseAndPrintList(list);
//search
System.out.println("searching for element with data 13");
if (list.search(list.head, 13))
System.out.println("Yes, given data is present in the list");
else
System.out.println("No, given data is not present in the list");
list.traverseAndPrintList(list);
//size of the list
System.out.println("size of the list at the end: " + list.size(list));
System.out.println("Add element 99 at 3rd position");
list.insertAfter(list.head.next,99 );
list.traverseAndPrintList(list);
}
}