Integer to Roman

Given an integer, convert it to a roman numeral.

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

Solution

Buffer the roman numbers.

Complexity

时间复杂度 O(n),空间复杂度 O(1)

Code

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