[LeetCode] Roman To Integer

Given a roman numeral, convert it to an integer.


Input is guaranteed to be within the range from 1 to 3999.

public int RomanToInt(String s) {
        HashMap romanIntMap = new HashMap();
        romanIntMap.put('M', 1000);
        romanIntMap.put('D', 500); 
        romanIntMap.put('C', 100);
        romanIntMap.put('L', 50);
        romanIntMap.put('X', 10);     
        romanIntMap.put('V', 5);
        romanIntMap.put('I', 1);
      
        int num = 0;
        
        for(int i = 0; i < s.length(); i++){
            int value = romanIntMap.get(s.charAt(i));
            
            if( (i != s.length() - 1) && value < romanIntMap.get(s.charAt(i+1))){
                num -= value;
                continue;
            }
            
            num +=value;
        }
        
        return num;
    }