RomanNumeral.java

package tudelft.sqt;

import java.util.HashMap;
import java.util.Map;

public class RomanNumeral {

	private static Map<Character, Integer> map;

	static {
		map = new HashMap<Character, Integer>() {{
			put('I', 1);
			put('V', 5);
			put('X', 10);
			put('L', 50);
			put('C', 100);
			put('D', 500);
			put('M', 1000);
		}};
	}

	public int romanToInt(String s) {
		int convertedNumber = 0;
		for(int i = 0; i < s.length(); i++) {
			int currentNumber = map.get(s.charAt(i));
			int next = i+1 < s.length() ?
					map.get(s.charAt(i+1)) : 0;

			if(currentNumber > next)
				convertedNumber += currentNumber;
			else
				convertedNumber -= currentNumber;
		}

		return convertedNumber;

	}
}