本題沒啥難度，就是技巧性的東西。

public class integerToRoman12 {
    public String intToRoman(int num) {
        StringBuilder sb = new StringBuilder();
        int[] values =    {1000,900, 500,400,100, 90,  50, 40, 10,  9,   5,   4,  1};
        String[] romans = {"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};
        
 
for(int i=0;i<values.length;i++) {
            while(num>=values[i]) {
                sb.append(romans[i]);
                num-=values[i];
            }
        }
        return sb.toString();
    }
}

37ms,96.88%.

Leetcode12 Integer to Roman