diff src/edu/unc/utils/RomanNumeral.java @ 2:e16016635b2a

Uploaded

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/edu/unc/utils/RomanNumeral.java	Mon Feb 13 22:12:06 2012 -0500
@@ -0,0 +1,57 @@
+package edu.unc.utils;
+
+// Rudimentary Class for doing Arabic Integer -> Roman Numeral conversion
+// Adapted by Timothy Palpant
+// File   : gui/componenents/calculators/Roman.java
+// Description: A static method for converting binary integers to Roman numbers.
+// Illustrates: Static inner value class, StringBuffer, throw exceptions.
+// Author : Fred Swartz - 2006-12-29 - Placed in public domain.
+public class RomanNumeral {
+
+	// This could be alternatively be done with parallel arrays.
+	// Another alternative would be Pair<Integer, String>
+	final static RomanValue[] ROMAN_VALUE_TABLE = {
+		new RomanValue(1000, "M"),
+		new RomanValue( 900, "CM"),
+		new RomanValue( 500, "D"),
+		new RomanValue( 400, "CD"),
+		new RomanValue( 100, "C"),
+		new RomanValue(  90, "XC"),
+		new RomanValue(  50, "L"),
+		new RomanValue(  40, "XL"),
+		new RomanValue(  10, "X"),
+		new RomanValue(   9, "IX"),
+		new RomanValue(   5, "V"),
+		new RomanValue(   4, "IV"),
+		new RomanValue(   1, "I")
+	};
+
+	public static String int2roman(int n) {
+		if (n >= 4000  || n < 1) {
+			throw new NumberFormatException("Numbers must be in range 1-3999");
+		}
+		StringBuilder result = new StringBuilder(10);
+
+		//... Start with largest value, and work toward smallest.
+		for (RomanValue equiv : ROMAN_VALUE_TABLE) {
+			//... Remove as many of this value as possible (maybe none).
+			while (n >= equiv.intVal) {
+				n -= equiv.intVal;            // Subtract value.
+				result.append(equiv.romVal);  // Add roman equivalent.
+			}
+		}
+		return result.toString();
+	}
+
+	private static class RomanValue {
+		//... No need to make this fields private because they are
+		//    used only in this private value class.
+		int    intVal;     // Integer value.
+		String romVal;     // Equivalent roman numeral.
+
+		RomanValue(int dec, String rom) {
+			this.intVal = dec;
+			this.romVal = rom;
+		}
+	}
+}
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