0012-integer-to-roman.js

/**
 * https://leetcode.com/problems/integer-to-roman/
 * @param {number} num
 * @return {string}
 */

var intToRoman = function (num) {
    let ans = '';

    while (num !== 0) {
        //M == 1000
        if (num >= 1000) {
            num -= 1000;
            ans += 'M';
        }
        //CM == 900
        else if (num >= 900) {
            num -= 900;
            ans += 'CM';
        }
        //D == 500
        else if (num >= 500) {
            num -= 500;
            ans += 'D';
        }
        //CD == 400
        else if (num >= 400) {
            num -= 400;
            ans += 'CD';
        }
        //C == 100
        else if (num >= 100) {
            num -= 100;
            ans += 'C';
        }
        //XC == 90
        else if (num >= 90) {
            num -= 90;
            ans += 'XC';
        }
        //L == 50;
        else if (num >= 50) {
            num -= 50;
            ans += 'L';
        }
        //XL == 40
        else if (num >= 40) {
            num -= 40;
            ans += 'XL';
        }
        //X == 10
        else if (num >= 10) {
            num -= 10;
            ans += 'X';
        }
        //IX == 9
        else if (num >= 9) {
            num -= 9;
            ans += 'IX';
        }
        //V == 5
        else if (num >= 5) {
            num -= 5;
            ans += 'V';
        }
        //IV == 4
        else if (num >= 4) {
            num -= 4;
            ans += 'IV';
        }
        //II == 2
        else if (num >= 2) {
            num -= 2;
            ans += 'II';
        }
        //I == 1
        else {
            num -= 1;
            ans += 'I';
        }
    }
    return ans;
};