Converting Integers to Roman Numerals - Java

     Roman Number are a system of numerical notations used by the Romans.

1 = I 5 = V 10 = X 50 = L 100 = C 500 = D 1000 = M = I 5000 = V 10,000 = X 50,000 = L 100,000 = C = I 500,000 = D = V 1,000,000 = M = X 5,000,000 = V = L 10,000,000 = X = C 50,000,000 = L = D 100,000,000  = C = M 500,000,000  = D 1,000,000,000 = M nn = 1000×nn nn = 100,000×nn nn = 1,000,000×nn

import java.util.*;
class RomanCounting {

  public static void main(String[] args) {
  int num;
  System.out.println("please the number smallest than 999999");
  System.out.println("According to automated program show 5000 as |V| and 10000 as |X| "
    + "and \n 50000 "
    + "as |L| and 100000 as |C| and 500000 as |D| and last as 1000000 as |M| ");
  Scanner obj = new Scanner(System.in);
  num = obj.nextInt();
  String str = String.valueOf(num);
  char []arr = str.toCharArray();

  int len = str.length();
  int count[] = new int[10];
  for(int i=0;i<len;i++){
      count[i] = (int)arr[i]-48; }
    
  String ones[] = new String[]{"","I","II","III","IV","V","VI","VII","VIII","IX","X"}; 
  String tens[] = new String[]{"","X","XX","XXX","XL","L","LX","LXX","LXXX","XC","C"};
  String hundred[] = new String[]{"","C","CC","CCC","CD","D","DC","DCC","DCCC","CM","M"};
  String thousand[] = new String[]{"","M","MM","MMM","MMMM","|V|","|V|M","|V|MM","|V|MMM",
                             "M|X|","|X|"};
  
  String TenThousand[] = new String[]{"","|X|","|X||X|","|X||X||X|","|X||L|","|L||X|",
                                   "|L||X||X|","|L||X||X|","|C||L|","|C|"};
  
  String[] HundredThousand = new String[]{"","|C|","|C||C|","|C||C||C|","|C||D|","|D|",
                                      "|D||C|","|D||C||C|","|D||M|","|M|"};
  if(len==6){
   String romancounting = HundredThousand[count[0]]+ TenThousand[count[1]]+ thousand[count[2]]
                     + hundred[count[3]] + tens[count[4]] + ones[count[5]];
   System.out.println(romancounting);
  }
  else if(len==5){ 
    String romancounting = TenThousand[count[0]]+ thousand[count[1]]+ hundred[count[2]] + 
      tens[count[3]] + ones[count[4]];
    System.out.println(romancounting);
  }
  else if(len==4){
   String romancounting = thousand[count[0]]+ hundred[count[1]] + tens[count[2]] + ones[count[3]];
   System.out.println(romancounting);
     }
  else if(len==3)
  {
  String romancounting = hundred[count[0]]+tens[count[1]]+ones[count[2]];
    System.out.println(romancounting);
  }
  else if(len==2){
     String romancounting = tens[count[0]]+ones[count[1]];
     System.out.println(romancounting);
         }
  else{
   System.out.println("Sorrt But number is invalid! OutOfRange👌"); }
     
   System.out.println("Thanks for using your automated software");
  }
  }

For Output : OUTPUT

Count the Occurrence of Character in the Linked List

~ Create an array.

~ One By One place the  character on array  on based on ASCII Value .

~ then, check the value of every index and find greater value/Occurence of Character.

public class LinkedlistOperation {

 Node head;
     class Node{
        int data;
        Node next;
           Node(int d){
               data =d;
               next = null;
       }    }

 public void OccurrenceNumber(){
    Node current= head;
    int arr[] = new int[256];
    while(current!=null){
       (arr[current.data])++;
       current =current.next;
          }
    System.out.println("Occurrence of all character are :");

    for(int i=0;i<256;i++){
        if(arr[i]>0){
          System.out.println(i+":" +arr[i]+" ");
   } } }

 public static void main(String ...args){
 LinkedlistOperation list = new LinkedlistOperation();
   list.push(1);
   list.push(1);
   list.push(3);
   list.push(4);
   list.push(2);
   list.push(2);
   list.push(15);
   list.push(20);
   list.push(1);
   list.push(1);
   list.push(3);
   list.push(4);
   list.push(5);
  list.OccurrenceNumber()  }

 OUTPUT :

Occurence of all Character are :
1:4 
2:2 
3:2 
4:2 
5:1 
15:1 
20:1 

Insertion Node in the Linkelist.

In this post, methods to insert a new node in linked list are discussed. A node can be added in three ways
1) At the front of the linked list
2) After a given node.
3) At the end of the linked list

public class Linkedlist {
 Node head;
 class Node{
  int data;
  Node next;
  Node(int d){
   data =d;
   next=null;
  } 
 }

// INSERT THE NODE AT THE BEGIN OF LINKEDLIST.

 
 public void insertAtfront(int new_data){
  
//  Node temp = head;
  Node new_node = new Node(new_data);
  new_node.next = head;
  head = new_node;
  
 } 

// INSERT THE NODE AT THE GIVEN POSITION IN LINKEDLIST.

 public void insertAtGiven(Node prev_node,int new_data)
 {
  if(prev_node == null){
   System.out.print("previous node can't be null");
   return;
   
  }
  Node new_node = new Node(new_data);
  new_node.next = prev_node.next;
  prev_node.next = new_node;
 }

// INSERT THE NODE  AT THE END OF THE LINKEDLIST.  

 public void insertAtEnd(int new_data){
  
  Node new_node = new Node(new_data);
  new_node.next = null;
  Node last = head;
  while(last.next!=null){
   last = last.next;
  
  }
  last.next= new_node;
  return;
  
 }

// TRAVERSING THE ELEMENT OF LINKEDLIST

 
 public void showlist(){
  Node tnode= head;
  while(tnode!=null){
   System.out.print(tnode.data+" ");
   tnode = tnode.next;
  }
 }

 // MAIN FUNCTION 

 public static void main(String ...args)  
{  
list.insertAtfront(10); 
 list.insertAtfront(12);
list.insertAtfront(14); 
 list.insertAtfront(16);
list.insertAtfront(18); 
 list.insertAtfront(19);
list.insertAtGiven(12,20);
list.insertAtGiven(20,22);
  list.insertAtEnd(24); 
 list.showlist();
 } 
}