changed error handling

02-Wielomiany/src/DivisionErrorException.java

@@ -0,0 +1,5 @@
+public class DivisionErrorException extends Throwable {
+    public DivisionErrorException() {
+        System.out.println("Division error!");
+    }
+}

02-Wielomiany/src/META-INF/MANIFEST.MF

@@ -0,0 +1,3 @@
+Manifest-Version: 1.0
+Main-Class: Main
+

02-Wielomiany/src/Main.java

@@ -0,0 +1,23 @@
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class Main {
+
+    public static void main(String[] args){
+        int n = Integer.parseInt(args[0]);
+        List<Integer> firstPolynomial = new ArrayList<>();
+        args[1] = args[1].substring(1, args[1].length()-1);
+        args[2] = args[2].substring(1, args[2].length()-1);
+        Arrays.asList(args[1].split( ",\\s*" )).forEach(factor -> firstPolynomial.add(Integer.valueOf(factor)));
+        List<Integer> secondPolynomial = new ArrayList<>();
+        Arrays.asList(args[2].split(",\\s*" )).forEach(factor -> secondPolynomial.add(Integer.valueOf(factor)));
+        PolynomialTask polynomialTask = new PolynomialTask(n, firstPolynomial, secondPolynomial);
+        System.out.print("[");
+        System.out.print(polynomialTask.printMultipliedPoly()
+                + ", " +  polynomialTask.printSubtractedPoly()
+                + ", " + polynomialTask.printGcd());
+        System.out.print("]");
+
+    }
+}

02-Wielomiany/src/MultiplierNotFoundException.java

@@ -0,0 +1,5 @@
+public class MultiplierNotFoundException extends Throwable {
+    public MultiplierNotFoundException() {
+        System.out.println("DivisionError");
+    }
+}

02-Wielomiany/src/PolynomialTask.java

@@ -0,0 +1,150 @@
+import java.util.Arrays;
+import java.util.List;
+
+public class PolynomialTask {
+    private int n;
+
+    private int[] firstPolynomialAsArray;
+    private int[] secondPolynomialAsArray;
+
+    public PolynomialTask(int n, List<Integer> firstPoly, List<Integer> secondPoly) {
+        this.n = n;
+        this.firstPolynomialAsArray = parseListToArray(firstPoly);
+        this.secondPolynomialAsArray = parseListToArray(secondPoly);
+    }
+
+    private int[] parseListToArray(List<Integer> polynomial) {
+        int[] result = new int[polynomial.size()];
+        for (int i = 0; i < polynomial.size(); i++) {
+            result[i] = polynomial.get(i);
+        }
+        return result;
+    }
+
+    private int[] multiplyPolynomials(int[] firstPolynomial, int[] secondPolynomial) {
+        int[] multiplied = new int[firstPolynomial.length + secondPolynomial.length - 1];
+        int sizeOfFirstPoly = firstPolynomial.length;
+        int sizeOfSecondPoly = secondPolynomial.length;
+        for (int i = 0; i < sizeOfFirstPoly; i++) {
+            for (int j = 0; j < sizeOfSecondPoly; j++)
+                multiplied[i + j] = (multiplied[i + j] + (firstPolynomial[i] * secondPolynomial[j])) % n;
+        }
+        return multiplied;
+    }
+
+    private int[] polyDiv(int[] polyOne, int[] polyTwo) {
+        if (polyOne.length < polyTwo.length) {
+            return null;
+        }
+        int firstPolyDeg = polyOne.length - 1;
+        int secondPolyDeg = polyTwo.length - 1;
+        int[] tempArr = new int[polyOne.length];
+        int[] result;
+        fillTemporaryArray(polyTwo, tempArr);
+        int tempMultiplier;
+        int shift = 0;
+        while (firstPolyDeg >= secondPolyDeg) {
+            parseNegativeElement(polyOne, firstPolyDeg);
+            tempMultiplier = findMultiplier(polyOne[firstPolyDeg], polyTwo[secondPolyDeg]);
+            tempArr = shiftValuesInArray(tempArr, shift);
+            tempArr = multiplyPolyByNumber(tempArr, tempMultiplier);
+            tempArr = moduloArray(tempArr);
+            polyOne = subtractTwoPolynomials(polyOne, tempArr);
+            firstPolyDeg--;
+            shift++;
+        }
+        result = Arrays.copyOf(polyOne, shift - 1);
+        return result;
+    }
+
+    private void fillTemporaryArray(int[] polyTwo, int[] tempArr) {
+        for (int i = 0; i < polyTwo.length; i++) {
+            tempArr[tempArr.length - 1 - i] = polyTwo[polyTwo.length - 1 - i];
+        }
+    }
+
+    private int[] subtractTwoPolynomials(int[] polyOne, int[] polyTwo) {
+        int[] result = new int[polyOne.length];
+        for (int i = 0; i < polyOne.length; i++) {
+            result[i] = polyOne[i] - polyTwo[i];
+        }
+        return result;
+    }
+
+    private int[] moduloArray(int[] array) {
+        for (int i = 0; i < array.length; i++) {
+            array[i] = array[i] % n;
+        }
+        return array;
+    }
+
+    private int[] multiplyPolyByNumber(int[] poly, int multiplier) {
+        for (int i = 0; i < poly.length; i++) {
+            poly[i] = poly[i] * multiplier;
+        }
+        return poly;
+    }
+
+    private int[] shiftValuesInArray(int[] array, int amount) {
+        if (amount == 0) {
+            return array;
+        } else {
+            int[] res = new int[array.length];
+            System.arraycopy(array, amount, res, 0, array.length - amount);
+            for (int j = array.length - amount + 1; j < res.length; j++) {
+                res[j] = 0;
+            }
+            return res;
+        }
+    }
+
+    private void parseNegativeElement(int[] polyOne, int firstPolyDeg) {
+        while (polyOne[firstPolyDeg] < 0) {
+            polyOne[firstPolyDeg] = n + polyOne[firstPolyDeg];
+        }
+    }
+
+    private int findMultiplier(int a, int b) {
+        for (int i = 0; i < n; i++) {
+            if (a == (b * i) % n) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    public String printMultipliedPoly() {
+        return Arrays.toString(multiplyPolynomials(firstPolynomialAsArray, secondPolynomialAsArray));
+    }
+
+    public String printSubtractedPoly() {
+        int[] result = polyDiv(firstPolynomialAsArray, secondPolynomialAsArray);
+        if (result == null) {
+            return "Division Error";
+        } else if (result.length == 0) {
+            return "[0]";
+        } else {
+            return Arrays.toString(polyDiv(firstPolynomialAsArray, secondPolynomialAsArray));
+        }
+    }
+
+    public String printGcd() {
+        int[] gcd = gcd(firstPolynomialAsArray, secondPolynomialAsArray);
+        if (gcd == null) {
+            return "Division Error";
+        } else
+            return Arrays.toString(gcd);
+    }
+
+    private int[] gcd(int[] firstPoly, int[] secondPoly) {
+        if (secondPoly.length == 0) {
+            return firstPoly;
+        }
+        if (firstPoly.length >= secondPoly.length) {
+            return gcd(secondPoly, polyDiv(firstPoly, secondPoly));
+        } else {
+            return gcd(secondPoly, polyDiv(secondPoly, firstPoly));
+        }
+    }
+
+}

Zadanie-03/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>

Zadanie-03/Zadanie-03.iml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
+

Zadanie-03/src/com/tylkowski/crc/CrcTask.java

@@ -0,0 +1,222 @@
+package com.tylkowski.crc;
+
+import java.util.Arrays;
+
+class CrcTask {
+    private String message;
+    private short[] messageAsShortArray;
+    private short[] polyGenerator;
+    private String rawMessage;
+
+    CrcTask(String message, String rawMessage) {
+        this.message = formatMessage(toBinary(message)) + "0000000000000000";
+        this.rawMessage = rawMessage;
+        createGeneratingPolynomial();
+    }
+
+    private String toBinary(String s) {
+        byte[] bytes = s.getBytes();
+        StringBuilder binary = new StringBuilder();
+        for (byte b : bytes) {
+            int val = b;
+            for (int i = 0; i < 8; i++) {
+                binary.append((val & 128) == 0 ? 0 : 1);
+                val <<= 1;
+            }
+        }
+        return binary.toString();
+    }
+
+    private String formatMessage(String message) {
+        int firstNonZeroVal = 0;
+        boolean found = false;
+        StringBuilder validString = new StringBuilder();
+        while (!found && firstNonZeroVal < message.length()) {
+            if (message.charAt(firstNonZeroVal) == 48) {
+                firstNonZeroVal++;
+            } else {
+                found = true;
+            }
+        }
+
+        for (int i = firstNonZeroVal; i < message.length(); i++) {
+            if (message.charAt(i) == 48) {
+                validString.append(0);
+            } else {
+                validString.append(1);
+            }
+        }
+        StringBuilder msg = new StringBuilder(validString.toString());
+        while (msg.length() % 8 != 0) {
+            msg.insert(0, "0");
+        }
+
+        return msg.toString();
+    }
+
+    private String generateFCS() {
+        while (true) {
+            if (messageAsShortArray[0] == 0) {
+                messageAsShortArray = Arrays.copyOfRange(messageAsShortArray, 1, messageAsShortArray.length);
+            } else {
+                short[] piece = Arrays.copyOfRange(messageAsShortArray, 0, Math.min(polyGenerator.length, messageAsShortArray.length));
+                if (piece.length < polyGenerator.length) {
+                    fillPolynomial(piece);
+                    return "" + getCharFromShortArray(piece, 0, 8) + getCharFromShortArray(piece, piece.length - 8, piece.length);
+                }
+                short[] remainder = calcXOR(piece, polyGenerator);
+                remainder = removeUnecessaryZeros(remainder);
+                messageAsShortArray = createMessageFromRemainderAndPartFromOldMessage(remainder, messageAsShortArray);
+            }
+
+
+        }
+
+    }
+
+    private short[] createMessageFromRemainderAndPartFromOldMessage(short[] remainder, short[] msg) {
+        short[] tempArr = new short[remainder.length + msg.length - polyGenerator.length];
+        System.arraycopy(remainder, 0, tempArr, 0, remainder.length);
+        int diff = polyGenerator.length - remainder.length;
+        System.arraycopy(msg, remainder.length + diff, tempArr, remainder.length, msg.length - diff - remainder.length);
+        msg = tempArr;
+        return msg;
+    }
+
+    private short[] removeUnecessaryZeros(short[] remainder) {
+        int firstNonZeroVal = 0;
+        boolean found = false;
+        while (!found && firstNonZeroVal < remainder.length) {
+            if (remainder[firstNonZeroVal] == 0) {
+                firstNonZeroVal++;
+            } else {
+                found = true;
+            }
+        }
+        return Arrays.copyOfRange(remainder, firstNonZeroVal, remainder.length);
+    }
+
+    private short[] calcXOR(short[] chunk, short[] polyGenerator) {
+        int a = Integer.parseInt(shortArrayToBinaryString(chunk), 2);
+        int b = Integer.parseInt(shortArrayToBinaryString(polyGenerator), 2);
+        String binaryString = Integer.toBinaryString(a ^ b);
+        return convertBinaryStringToShortArray(binaryString);
+    }
+
+    private String shortArrayToBinaryString(short[] value) {
+        StringBuilder binaryString = new StringBuilder();
+        for (Short a : value) {
+            binaryString.append(a);
+        }
+        return binaryString.toString();
+    }
+
+    private char getCharFromShortArray(short[] chunk, int from, int to) {
+        short[] sign = Arrays.copyOfRange(chunk, from, to);
+        int character = Integer.parseInt(shortArrayToBinaryString(sign), 2);
+//        System.out.println(character);
+        return (char) character;
+    }
+
+    private void fillPolynomial(short[] chunk) {
+        while (chunk.length % 8 != 0) {
+            chunk = addZeroAtBeginningOfArray(chunk);
+        }
+    }
+
+    private short[] addZeroAtBeginningOfArray(short[] chunk) {
+        short[] letterTemp = new short[chunk.length + 1];
+        letterTemp[0] = 0;
+        System.arraycopy(chunk, 0, letterTemp, 1, chunk.length);
+        return letterTemp;
+    }
+
+    private void convertMessageToBinaryShortArray() {
+        messageAsShortArray = new short[message.length()];
+        for (int i = 0; i < polyGenerator.length; i++) {
+            if (message.charAt(i) == 48) {
+                messageAsShortArray[i] = 0;
+            } else {
+                messageAsShortArray[i] = 1;
+            }
+        }
+    }
+
+    private short[] convertBinaryStringToShortArray(String binaryString) {
+        short[] shortArray = new short[binaryString.length()];
+        for (int i = 0; i < binaryString.length(); i++) {
+            if (binaryString.charAt(i) == 48) {
+                shortArray[i] = 0;
+            } else {
+                shortArray[i] = 1;
+            }
+        }
+        return shortArray;
+    }
+
+    private void createGeneratingPolynomial() {
+        polyGenerator = new short[17];
+        for (int i = 0; i < 17; i++) {
+            polyGenerator[i] = 0;
+        }
+        polyGenerator[0] = 1;
+        polyGenerator[4] = 1;
+        polyGenerator[11] = 1;
+        polyGenerator[16] = 1;
+    }
+
+    private short[] swapPolynomialValues(short[] poly) {
+        for (int i = 0; i < polyGenerator.length - 1; i++) {
+            poly[i] = (short) ((poly[i] + 1) % 2);
+        }
+        return poly;
+    }
+
+    String encode() {
+        convertMessageToBinaryShortArray();
+        messageAsShortArray = swapPolynomialValues(messageAsShortArray);
+        return rawMessage + generateFCS();
+    }
+
+    boolean decode(String encodedString) {
+        encodedString = toBinary(encodedString);
+        encodedString = fillPolyTo8(encodedString);
+        short[] encodedShortArray = convertBinaryStringToShortArray(encodedString);
+        encodedShortArray = swapPolynomialValues(encodedShortArray);
+        while (true) {
+            if (shortArrayContains(encodedShortArray, 1)) {
+                return true;
+            }
+
+            if (encodedShortArray[0] == 0) {
+                encodedShortArray = Arrays.copyOfRange(encodedShortArray, 1, encodedShortArray.length);
+            } else {
+                short[] piece = Arrays.copyOfRange(encodedShortArray, 0, Math.min(polyGenerator.length, encodedShortArray.length));
+                if (piece.length < polyGenerator.length) {
+                    return false;
+                }
+
+                short[] remainder = calcXOR(piece, polyGenerator);
+                remainder = removeUnecessaryZeros(remainder);
+                encodedShortArray = createMessageFromRemainderAndPartFromOldMessage(remainder, encodedShortArray);
+            }
+        }
+    }
+
+    private boolean shortArrayContains(short[] encodedShortArray, int value) {
+        for (short item : encodedShortArray) {
+            if (item == value) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private String fillPolyTo8(String encodedString) {
+        StringBuilder stringBuilder = new StringBuilder(encodedString);
+        while (stringBuilder.length() % 8 != 0) {
+            stringBuilder.insert(0, "0");
+        }
+        return stringBuilder.toString();
+    }
+}

Zadanie-03/src/com/tylkowski/crc/Main.java

@@ -0,0 +1,15 @@
+package com.tylkowski.crc;
+
+public class Main {
+
+    public static void main(String[] args) {
+        // ex. in command line type "a"
+        CrcTask crcTask = new CrcTask(args[0], args[0]);
+        System.out.println(crcTask.encode());
+        String input = crcTask.encode();
+        if (input.length() >= 3) System.out.println(crcTask.decode(input));
+
+    }
+
+
+}