12.整数转罗马数字

方法：模拟

分析罗马数字的规则是：对于罗马数字从左到右的每一位，选择尽可能大的符号值

根据罗马数字的唯一表示法，为了表示一个给定的整数num，寻找不超过num的最大符号值，将num减去该符号值，然后继续寻找不超过num的最大符号值，将该符号拼接再上一个找到的符号之后，循环直至num为0，最后得到的字符串即为num的罗马数字表示

class Solution {int[] values ={1000,900,500,400,100,90,50,40,10,9,5,4,1};String[] symbols = {"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};public String intToRoman(int num) {StringBuffer s = new StringBuffer();for(int i = 0;i < values.length;i++){int value = values[i];while(num >= value){num -= value;s.append(symbols[i]);}if(num == 0){break;}}return s.toString();}
}