import junit.framework.TestCase;

public class RomanNumerEncoderTest extends TestCase {

    public void testEncode() {
        assertEncode("", 0);
        assertEncode("I", 1);
        assertEncode("II", 2);
        assertEncode("III", 3);
        assertEncode("IV", 4);
        assertEncode("V", 5);
        assertEncode("VI", 6);
        assertEncode("IX", 9);
        assertEncode("X", 10);
        assertEncode("XI", 11);
        assertEncode("XL", 40);
        assertEncode("L", 50);
        assertEncode("XC", 90);
        assertEncode("C", 100);
        assertEncode("D", 500);
        assertEncode("M", 1000);
        assertEncode("MDCCCLXXVIII", 1878);
        assertEncode("MCMLIII", 1953);
        assertEncode("MMXI", 2011);
        assertEncode("XCIX", 99);
        assertEncode("CMXC", 990);
    }

    private void assertEncode(String numeral, int arabicNumber) {
        assertEquals(numeral, new RomanNumberEncoder().encode(arabicNumber));
    }

}

class RomanNumberEncoder {

    private static final int[] decimalValueOfRomanNumeral = {
        1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1
    };
    private static final String[] romanNumeral = {
        "M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"
    };

    private int currentArabicRemainder;
    private StringBuilder romanNumeralTemp = new StringBuilder();

    public String encode(int pArabicNumber) {
        initTemporaryMenbers(pArabicNumber);
        appendElementaryNumeralsAsNeeded();
        return encodedRomanNumeralString();
    }

    private void initTemporaryMenbers(int pArabicNumber) {
        currentArabicRemainder = pArabicNumber;
        romanNumeralTemp = new StringBuilder();
    }

    private void appendElementaryNumeralsAsNeeded() {
        for (int i = 0; isMoreElementarNumeralsNeededAndAvailable(i); i++) {
            appendElementaryNumeralGroupForIndex(i);
        }
    }

    private boolean isMoreElementarNumeralsNeededAndAvailable(int i) {
        return (i < decimalValueOfRomanNumeral.length)
        && (0 < currentArabicRemainder);
    }

    private void appendElementaryNumeralGroupForIndex(int pElementaryNumeralIndex) {
        while (currentArabicRemainder >= decimalValueOfRomanNumeral[pElementaryNumeralIndex]) {
            romanNumeralTemp.append(romanNumeral[pElementaryNumeralIndex]);
            currentArabicRemainder -= decimalValueOfRomanNumeral[pElementaryNumeralIndex];
        }
    }

    private String encodedRomanNumeralString() {
        assert (0 == currentArabicRemainder);
        return this.romanNumeralTemp.toString();
    }
}