// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// POSSIBILITY OF SUCH DAMAGE.
package jodd.format;
/**
* Conversion to and from Roman numbers.
*/
public class RomanNumber {
private static final int[] VALUES = new int[] {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};
private static final String[] LETTERS = new String[] {"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
/**
* Converts to Roman number.
*/
public static String convertToRoman(int value) {
if (value <= 0) {
throw new IllegalArgumentException();
}
StringBuilder roman = new StringBuilder();
int n = value;
for (int i = 0; i < LETTERS.length; i++) {
while (n >= VALUES[i]) {
roman.append(LETTERS[i]);
n -= VALUES[i];
}
}
return roman.toString();
}
/**
* Converts to Arabic numbers.
*/
public static int convertToArabic(String roman) {
int start = 0, value = 0;
for (int i = 0; i < LETTERS.length; i++) {
while (roman.startsWith(LETTERS[i], start)) {
value += VALUES[i];
start += LETTERS[i].length();
}
}
return start == roman.length() ? value : -1;
}
/**
* Checks if some string is valid roman number.
*/
public static boolean isValidRomanNumber(String roman) {
try {
return roman.equals(convertToRoman(convertToArabic(roman)));
} catch (IllegalArgumentException ignore) {
return false;
}
}
}