Question

Exercise 1:

Write a program that converts a number entered in Roman numerals to decimal. Your program should consist of a class, say, Roman. An object of type Roman should do the following:

1. Store the number as a Roman numeral.
2. Convert and store the number into decimal.
3. Print the number as a Roman numeral or decimal number as requested by the user.

The decimal values of the Roman numerals are:

M 1000

D 500

C 100

L 50

X 10

V 5

I 1

4. Your class must contain the method romanToDecimal to convert a Roman numeral into its equivalent decimal number
5. Test your program using the following Roman numerals: MCXIV, CCCLIX, and MDCLXVI.

Answer 1

solution:

import java.util.*;
public class Roman
{static Scanner in=new Scanner(System.in);
public static void main(String[] args)
{String input;
char RD;
System.out.print("Enter a roman number: ");
input=in.nextLine();
Roman a=new Roman(input);
System.out.println("Output as Roman number or decimal (enter R or D): ");
RD=in.next().charAt(0);
if(Character.toUpperCase(RD)=='R')
System.out.println(a.getRoman());
else
System.out.println(a.getDecimal());
}
}

public class Roman
{private String roman;
private int decimal;
public Roman(String r)
{int i,prev=1000;
roman=r;
decimal=0;
for(i=0;i<r.length();i++)
{switch(r.charAt(i))
{case 'm':
case 'M': decimal+=1000;
if(prev<1000)
decimal-=(2*prev);
prev=1000;
break;
case 'd':
case 'D': decimal+=500;
if(prev<500)
decimal-=(2*prev);
prev=500;
break;
case 'c':
case 'C': decimal+=100;
if(prev<100)
decimal-=(2*prev);
prev=100;
break;
case 'l':
case 'L':decimal+=50;
if(prev<50)
decimal-=(2*prev);
prev=50;
break;
case 'x':
case 'X': decimal+=10;
if(prev<10)
decimal-=(2*prev);
prev=10;
break;
case 'v':
case 'V': decimal+=5;
if(prev<5)
decimal-=(2*prev);
prev=5;
break;
case 'i':
case 'I': decimal++;
prev=1;
}
}
}

public int getDecimal()
{return decimal;
}

public String getRoman()
{return roman;
}
}

please give me thumb up