Integer to Roman

Problem:
Given an integer, convert it to a roman numeral.

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

Solution:

public String intToRoman(int num) {
    int[] nums = {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"};
    StringBuilder res = new StringBuilder();
    int i=0;
    while (num>0) {
        int times = num / nums[i];
        num -= nums[i]*times;
        for (; times>0; times--) {
            res.append(symbols[i]);
        }
        ++i;
    }
    return res.toString();
}

Complexity:

time - O(1)
space - O(1)

Links and credits:
http://discuss.leetcode.com/questions/194/integer-to-roman