/**
 * @param {number} num
 * @return {string}
 */
var intToRoman = function(num) {
    const romanKey = ['1000', '900', '500', '400', '100', '90', '50', '40', '10', '9', '5', '4', '1']
    const romanVal = ['M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I']
    let result = ''
    romanKey.forEach((item, index) => {
      // 从输入的数字减去最大的数字，同时将其罗马数字加到结果中
        while(num >= item){
            result += romanVal[index]
            num -= item
        }
    })
    return result
};