Question 1

Integer to Roman

Given an integer, convert it to a roman numeral.

Input is guaranteed to be within the range from 1 to 3999

What we need to notice is the thing like "CM", the smaller one followed by the big one, where you need to substract the smaller one.

public class Solution {    public String intToRoman(int num) {        String result = "";        String[] set1 = {"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};        int[] set2 = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};                for (int i = 0; num != 0; i ++){            while (num >= set2[i]){                result += set1[i];                num -= set2[i];            }        }                return result;    }}