Java将整数转换为罗马数字

使用Java TreeMap和递归的紧凑实现：

import java.util.TreeMap;public class RomanNumber {    private final static TreeMap<Integer, String> map = new TreeMap<Integer, String>();    static {        map.put(1000, "M");        map.put(900, "CM");        map.put(500, "D");        map.put(400, "CD");        map.put(100, "C");        map.put(90, "XC");        map.put(50, "L");        map.put(40, "XL");        map.put(10, "X");        map.put(9, "IX");        map.put(5, "V");        map.put(4, "IV");        map.put(1, "I");    }    public final static String toRoman(int number) {        int l =  map.floorKey(number);        if ( number == l ) { return map.get(number);        }        return map.get(l) + toRoman(number-l);    }}

测试：

public void testRomanConversion() {    for (int i = 1; i<= 100; i++) {        System.out.println(i+"t =t "+RomanNumber.toRoman(i));    }}