Roman2Integer x2

class Solution {
    public int romanToInt(String s) {
        Map<Character, Integer> romanToInteger = Map.of(
            'I', 1,
            'V', 5,
            'X', 10,
            'L', 50,
            'C', 100,
            'D', 500,
            'M', 1000
        );

        int result = 0;

        for (int i = 0; i < s.length(); i++) {

            Character c = s.charAt(i);
            Character cNext = Character.MIN_VALUE;
            boolean shouldSubtract = false;
            if (i+1 < s.length()) {

                cNext = s.charAt(i+1);
                switch(c) {
                    case 'I':
                        if (cNext == 'V' || cNext == 'X') {
                            shouldSubtract = true;
                        }
                        break;
                    case 'X':
                        if (cNext == 'L' || cNext == 'C') {
                            shouldSubtract = true;
                        }
                        break;
                    case 'C':
                        if (cNext == 'D' || cNext == 'M') {
                            shouldSubtract = true;
                        }
                        break;
                }
            }

            if (shouldSubtract) {
                result += (romanToInteger.get(cNext) - romanToInteger.get(c));
                i++;
            }
            else {
                result += romanToInteger.get(c);
            }
        }
        return result;
    }
}