Demo_2.java

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

class RomanToInteger{
 public int romanToInt(String s) { // XIV
 Map<Character, Integer> map = new HashMap<Character, Integer>();
 map.put('I', 1);
 map.put('V', 5);
 map.put('X', 10);
 map.put('L', 50);
 map.put('C', 100);
 map.put('D', 500);
 map.put('M', 1000);
 
 int result = 0;
 int i=0;
 while(i<s.length()){
 int currentVal = map.get(s.charAt(i));

 int nextVal = 0;
 if(i+1<s.length()){
 nextVal = map.get(s.charAt(i+1));
 }

 if(nextVal > currentVal){
 result += (nextVal - currentVal);
 i = i+2;
 } else {
 result += currentVal;
 i++;
 }
 }

 return result;
 }
}

public class Demo_2 {
 public static void main(String[] args) {
 RomanToInteger obj = new RomanToInteger();
 int n = obj.romanToInt("XCVII");// 97
 System.out.println(n);
 }
}