roman_to_integer.dart

// https://leetcode.com/problems/roman-to-integer/
class Solution {
  int romanToInt(String s) {
    final values = <String, int>{
      'I': 1,
      'V': 5,
      'X': 10,
      'L': 50,
      'C': 100,
      'D': 500,
      'M': 1000,
    };
    int result = 0;
    for (int i = s.length - 1; i >= 0; i--) {
      int curr = values[s[i]]!;
      if (curr * 4 < result) {
        result -= curr;
      } else {
        result += curr;
      }
    }
    return result;
  }
}