Roman numerals solution

roman-numerals-solution/README.md

@@ -0,0 +1,31 @@
+Hi,
+
+
+## Implementation plan
+
+* Create java main class with ability to read input from cmd pipe
+* Implement convert algorithm
+* Catch all possible exceptions
+* Make some refac/add test/finally review
+
+## User guide
+
+1. Compile java source file:
+
+	G:>javac RomanNumeralsConvert.java
+
+2. Run java application with cmd pipe:
+
+	G:>echo "1 12 103" | java RomanNumeralsConvert
+	I
+	XII
+	CIII
+
+3. Add "-test" flag to run application in test mode:
+
+	G:>echo "1 12 103" | java RomanNumeralsConvert -test
+	1 => I passed.
+	12 => XII passed.
+	103 => CIII passed.
+	10char3 => 10char3, illegal argument error - is not valid digital number. passed.
+	10399911 => 10399911, range bound error - number should be in the range [1 - 3999]. passed.

roman-numerals-solution/RomanNumeralsConvert.java

@@ -0,0 +1,167 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class RomanNumeralsConvert {
+
+	public final static String onesArray[] = { "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX" };
+	public final static String tensArray[] = { "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC" };
+	public final static String hundredsArray[] = { "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM" };
+
+	public final static String TEST_MOD = "-test";
+	public final static String ONE = "I";
+	public final static String TWELVE = "XII";
+	public final static String ONE_HUNDRED_AND_THREE = "CIII";
+
+	private static String[] numArray;
+
+	public static void main(String[] args) {
+
+		if (args.length > 0) {
+			if (args.length > 1 || !TEST_MOD.equals(args[0])) {
+				System.out.println("Only one flag supports: - test");
+			} else {
+				runTest();
+			}
+		} else {
+			readInput();
+
+			validate();
+
+			convert();
+
+			printResult();
+		}
+
+	}
+
+	public static void readInput() {
+		try (BufferedReader in = new BufferedReader(new InputStreamReader(System.in));) {
+			String line;
+			while ((line = in.readLine()) != null) {
+				line = line.replace("\"", "").trim();
+				numArray = line.split("\\s+");
+			}
+		} catch (final IOException e) {
+			System.err.println("IOException reading System.in" + e);
+		}
+	}
+
+	public static void validate() {
+		for (int i = 0; i < numArray.length; i++) {
+			final String numStr = numArray[i];
+			boolean e = true;
+			for (int k = 0; k < numStr.length(); k++) {
+				if (Character.isDigit(numStr.charAt(k)) == false) {
+					numArray[i] = numArray[i] + ", illegal argument error - is not valid digital number.";
+					e = false;
+					break;
+				}
+			}
+
+			if (e) {
+				final int num = Integer.parseInt(numStr);
+				if (num > 3999 || num < 1) {
+					numArray[i] = numArray[i] + ", range bound error - number should be in the range [1 - 3999].";
+				}
+			}
+		}
+	}
+
+	public static void convert() {
+		for (int i = 0; i < numArray.length; i++) {
+			final String numStr = numArray[i];
+
+			if (numStr.contains("error")) {
+				continue;
+			}
+
+			String Roman = "";
+			int num = Integer.parseInt(numStr);
+
+			final int ones = num % 10;
+
+			num = (num - ones) / 10;
+			final int tens = num % 10;
+
+			num = (num - tens) / 10;
+			final int hundreds = num % 10;
+
+			num = (num - hundreds) / 10;
+			for (int n = 0; n < num; n++) {
+				Roman += "M";
+			}
+
+			if (hundreds >= 1) {
+				Roman += hundredsArray[hundreds - 1];
+			}
+
+			if (tens >= 1) {
+				Roman += tensArray[tens - 1];
+			}
+
+			if (ones >= 1) {
+				Roman += onesArray[ones - 1];
+			}
+
+			numArray[i] = String.valueOf(Roman);
+		}
+	}
+
+	public static void printResult() {
+		for (int i = 0; i < numArray.length; i++) {
+			System.out.println(numArray[i]);
+		}
+
+	}
+
+	public static void runTest() {
+		numArray = new String[5];
+
+		numArray[0] = "1";
+		numArray[1] = "12";
+		numArray[2] = "103";
+
+		numArray[3] = "10char3";
+		numArray[4] = "10399911";
+
+		validate();
+
+		convert();
+
+		System.out.print("1 => " + numArray[0]);
+		if (ONE.equals(numArray[0])) {
+			System.out.println(" passed.");
+		} else {
+			System.out.println(" failed.");
+		}
+
+		System.out.print("12 => " + numArray[1]);
+		if (TWELVE.equals(numArray[1])) {
+			System.out.println(" passed.");
+		} else {
+			System.out.println(" failed.");
+		}
+
+		System.out.print("103 => " + numArray[2]);
+		if (ONE_HUNDRED_AND_THREE.equals(numArray[2])) {
+			System.out.println(" passed.");
+		} else {
+			System.out.println(" failed.");
+		}
+
+		System.out.print("10char3 => " + numArray[3]);
+		if ("10char3, illegal argument error - is not valid digital number.".equals(numArray[3])) {
+			System.out.println(" passed.");
+		} else {
+			System.out.println(" failed.");
+		}
+
+		System.out.print("10399911 => " + numArray[4]);
+		if ("10399911, range bound error - number should be in the range [1 - 3999].".equals(numArray[4])) {
+			System.out.println(" passed.");
+		} else {
+			System.out.println(" failed.");
+		}
+	}
+}