Assignment finished

src/RomanNumerals.java

@@ -1,8 +1,141 @@
 
 public class RomanNumerals {
 	public int convertToInteger(String romanNum) {
-		// To be Implemented
-		return 0;
+		String input=romanNum;
+		int numeric=0;
+		int subtraction=0;		
+		int lenght=input.length();
+		int i=0;
+		checkIfRepeated(input);//L, D or V can't be repeated
+		checkIf4inARow(input);//I, X, C or M can be repeated max 3 times in a row
+		checkTooHighSubtraction(input);//symbols I, X, and C can only be subtracted from the 2 next highest values
+		checkSubtractionsPerNumeral(input);//only one subtraction can be made per numeral
+		checkSubtractionOf5Symbols(input);//V, L and D can never be subtracted
+		checkInputCharacters(input);//only accept roman numbers as input
+
 
+		while(i<lenght) {
+
+			if(lenght==i+1) {//only one roman character inserted
+				numeric=numeric+getNumber(input.charAt(0));								
+			}
+			else if(getNumber(input.charAt(i))<getNumber(input.charAt(i+1))){				
+				subtraction=getNumber(input.charAt(i+1))-getNumber(input.charAt(i));
+				numeric=numeric+subtraction;
+				i++;
+				subtraction=0;
+			}
+			else {
+				numeric=numeric+getNumber(input.charAt(i));
+			}
+			i++;			
+		}
+
+		return numeric;		 
+	}
+
+	private void checkInputCharacters(String input) {
+		if (input.matches(".*[0-9].*") || !input.matches("[M|D|C|L|X|V|I]*")) {
+            throw new IllegalArgumentException();
+        }
+
+	}
+
+	private void checkSubtractionOf5Symbols(String input) {
+		int lenght=input.length();
+		int i=0;
+		while(i<lenght-1) {
+			if(getNumber(input.charAt(i))<getNumber(input.charAt(i+1))) {
+				if(input.charAt(i)=='V' || input.charAt(i)=='L' || input.charAt(i)=='D') {
+					throw new IllegalArgumentException();
+				}
+			}
+			i++;
+		}
+
+	}
+
+	private void checkSubtractionsPerNumeral(String input) {
+		int lenght=input.length();
+		int i=0;
+		while(i<lenght-1) {
+			if(getNumber(input.charAt(i))<getNumber(input.charAt(i+1))) {
+			if(i>0) {
+				if(getNumber(input.charAt(i-1))<=getNumber(input.charAt(i))) {
+					throw new IllegalArgumentException();
+				}
+			}}
+			i++;
+		}
+
+	}
+
+	private void checkTooHighSubtraction(String input) {
+		int a=input.indexOf("IL");
+		int b=input.indexOf("IC");
+		int c=input.indexOf("ID");
+		int d=input.indexOf("IM");
+		int e=input.indexOf("XD");
+		int f=input.indexOf("XM");
+
+		if(a>=0 || b>=0 || c>=0 || d>=0 || e>=0 || f>=0) {
+			throw new IllegalArgumentException();
+		}
+
+	}
+
+	private void checkIf4inARow(String input) {
+		int a=input.indexOf("IIII");
+		int b=input.indexOf("XXXX");
+		int c=input.indexOf("CCCC");
+		int d=input.indexOf("MMMM");
+
+		if (a>=0 || b>=0 || c>=0 || d>=0) {
+			throw new IllegalArgumentException("Invalid input");
+		}
+
+	}
+
+	private void checkIfRepeated(String input) {
+		int a=input.indexOf("VV");
+		int b=input.indexOf("LL");
+		int c=input.indexOf("DD");
+
+		if (a>=0 || b>=0 || c>=0) {
+			throw new IllegalArgumentException("Invalid input");
+		}
+	}
+
+	public int getNumber(char c) {
+
+		int number=0;
+		char symbol=c;
+
+		switch (symbol) {
+        case ('I'):
+            number = 1;
+            break;
+        case ('V'):
+            number = 5;
+            break;
+        case ('X'):
+        	number = 10;
+            break;
+        case ('L'):
+        	number = 50;
+            break;
+        case ('C'):
+        	number = 100;
+            break;
+        case ('D'):
+        	number = 500;
+            break;
+        case ('M'):
+        	number = 1000;
+            break;
+        }
+
+		return number;
 	}
+
 }

tests/TestRomanNumerals.java

@@ -5,8 +5,66 @@
 public class TestRomanNumerals {
 
 	@Test
-	public void test() {
-		fail("Not yet implemented");
+	public void RomanIReturns1() {
+		RomanNumerals nums = new RomanNumerals();
+		assertEquals("Fail",1, nums.convertToInteger("I"));	
+
 	}
-
+	@Test
+	public void RomanMReturns1000() {
+		RomanNumerals nums = new RomanNumerals();
+		assertEquals("Fail",1000, nums.convertToInteger("M"));	
+
+	}
+	@Test
+	public void AddSymbolValuesTogether() {
+		RomanNumerals nums = new RomanNumerals();
+		assertEquals("Fail", 200, nums.convertToInteger("CC"));
+	}
+	@Test
+	public void TestSubtractionCase() {
+		RomanNumerals nums = new RomanNumerals();
+		assertEquals("Fail", 4, nums.convertToInteger("IV"));
+	}
+	@Test
+	public void TestLongCombinations() {
+		RomanNumerals nums = new RomanNumerals();
+		assertEquals("Fail", 1984, nums.convertToInteger("MCMLXXXIV"));
+	}
+	@Test(expected=IllegalArgumentException.class)
+	public void RepeatedLVDthrowsException() {
+		RomanNumerals nums = new RomanNumerals();
+		nums.convertToInteger("IVV");
+	}
+	@Test(expected=IllegalArgumentException.class)
+	public void MoreThan3inARowthrowsException() {
+		RomanNumerals nums = new RomanNumerals();
+		nums.convertToInteger("MXXXXI");
+	}
+	@Test(expected=IllegalArgumentException.class)
+	public void TestInvalidSubtraction() {
+		RomanNumerals nums = new RomanNumerals();
+		nums.convertToInteger("XMD");	
+	}
+	@Test(expected=IllegalArgumentException.class)
+	public void TwoSubtractionsPerNumeralThrowsException() {
+		RomanNumerals nums = new RomanNumerals();
+		nums.convertToInteger("CCM");	
+	}
+	@Test(expected=IllegalArgumentException.class)
+	public void SubtractingLDorVThrowsException() {
+		RomanNumerals nums = new RomanNumerals();
+		nums.convertToInteger("DM");	
+	}
+	@Test(expected=IllegalArgumentException.class)
+	public void NonRomaSymbolsThrowsException() {
+		RomanNumerals nums = new RomanNumerals();
+		nums.convertToInteger("X1V");
+	}
+	@Test
+	public void TestFinishedProgramme() {
+		RomanNumerals nums = new RomanNumerals();
+		assertEquals("Fail", 2014, nums.convertToInteger("MMXIV"));
+	}
+
 }