Integer to Roman

Given an integer, convert it to a roman numeral.

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

 1 public class Solution {
 2     public String intToRoman(int num) {
 3         String romans[][] = new String[][]{
 4                 {"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"},
 5                 {"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"},
 6                 {"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"},
 7                 {"", "M", "MM", "MMM",}
 8         };
 9         String result = "";
10         int index = 0;
11         while(num != 0){
12             String temp = romans[index][num % 10];
13             result = temp + result;
14             index++;
15             num = num / 10;
16         }//while
17         
18         return result;
19     }
20 }

 下面是使用的贪心算法，每次减去最大的

 1 public class Solution {
 2     public String intToRoman(int num) {
 3         int array_int[] = new int[]{1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};
 4         String array_string[] = new String[]{"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
 5         
 6         StringBuffer sb = new StringBuffer();
 7         for(int i = 0; i < array_int.length; i++){
 8             while(num >= array_int[i]){
 9                 num -= array_int[i];
10                 sb.append(array_string[i]);
11             }//while
12         }//for
13         
14         return sb.toString();
15     }
16 }