13. Roman to Integer

Given a roman numeral, convert it to an integer.

Example:

III => 3

LVIII => 58

Solution

// When we loop through the string, we check 
// if current character has smaller value than the next character => It is subtractive form => Subtract the value from result
// Else we will add the value into result
function romanToInt(s: string): number {
  const map = new Map([
    ['I', 1],
    ['V', 5],
    ['X', 10],
    ['L', 50],
    ['C', 100],
    ['D', 500],
    ['M', 1000],
  ]);

  let result = 0;
  for (let i = 0; i < s.length; i++) {
    if (map.get(s[i]) < map.get(s[i + 1])) {
      result -= map.get(s[i]);
      continue;
    }

    result += map.get(s[i]);
  }

  return result;
}