Roman to Decimal

Converting Roman String to Decimal

Input: VI
Output : 6

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public class RomanToDecimal{ public static void romanToDecimal(String romanNumber){ int decimal = 0; int lastNumber = 0; String romanNumeral = romanNumber.toUpperCase(); for (int x = romanNumeral.length() - 1; x >= 0 ; x--){ char convertToDecimal = romanNumeral.charAt(x); switch (convertToDecimal){ case 'M': decimal = processDecimal(1000, lastNumber, decimal); lastNumber = 1000; break; case 'D': decimal = processDecimal(500, lastNumber, decimal); lastNumber = 500; break; case 'C': decimal = processDecimal(100, lastNumber, decimal); lastNumber = 100; break; case 'L': decimal = processDecimal(50, lastNumber, decimal); lastNumber = 50; break; case 'X': decimal = processDecimal(10, lastNumber, decimal); lastNumber = 10; break; case 'V': decimal = processDecimal(5, lastNumber, decimal); lastNumber = 5; break; case 'I': decimal = processDecimal(1, lastNumber, decimal); lastNumber = 1; break; } } System.out.println("Decimal number : "+decimal); } public static int processDecimal(int decimal, int lastNumber, int lastDecimal){ if (lastNumber > decimal) return lastDecimal - decimal; else return lastDecimal + decimal; } public static void main(java.lang.String args[]){ String roman = "VI"; romanToDecimal(roman); } }