LeetCode 12 Integer to Roman

Given an integer, convert it to a roman numeral.

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

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