<pre class="shiki github-dark shaku"><code>const rm = { 'I' : 1, 'V' : 5, 'X' : 10, 'L' : 50, 'C' : 100, 'D' : 500, 'M' : 1000};/** * @param {string} str - roman numeral string * @returns {number} integer */function romanToInteger(str) { let i = 0, sum = 0; while (i &lt; str.length) { let a = rm[str[i++]]; if (i &lt; str.length) { let b = rm[str[i]]; if (b &gt; a) { a = b - a; i++; } } sum += a; } return sum;}</code></pre>