LeetCode#12. Integer to Roman

• 题目：将1-3999的整数转成罗马数
• 难度：Medium

• 思路：罗马数字由7个基本数字构成

      I - 1    V - 5    X - 10    L - 50    C - 100    D - 500    M - 1000    便于记忆：v表示一个手指，x表示两个手指上下拼接，C是century百，L是C的一半表示50，M是Milles 1000

  一个整数可以用个位，十位，百位，千位上的数字来表示，所以用数组存储罗马数字，然后与阿拉伯数对应即可

• 代码：

public class Solution {    public String intToRoman(int num) {        String[] M = {"","M","MM","MMM"};        String[] C = {"","C","CC","CCC","CD","D","DC","DCC","DCCC","CM"};        String[] X = {"","X","XX","XXX","XL","L","LX","LXX","LXXX","XC"};        String[] I = {"","I","II","III","IV","V","VI","VII","VIII","IX"};        return M[num/1000]+C[(num/100)%10]+X[(num/10)%10]+I[num%10];    }}