Valerie Kristofic internship interview submission March 2019

kristoficSubmission/Decoder.java

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+import java.util.*;
+
+// Main class for parsing and decoding morse text given in flat file
+public class Decoder {
+    /* Variable initializations for morse and english alphabet */
+    private static final String A = ".-";
+    private static final String B = "-...";
+    private static final String C = "-.-.";
+    private static final String D = "-..";
+    private static final String E = ".";
+    private static final String F = "..-.";
+    private static final String G = "--.";
+    private static final String H = "....";
+    private static final String I = "..";
+    private static final String J = ".---";
+    private static final String K = "-.-";
+    private static final String L = ".-..";
+    private static final String M = "--";
+    private static final String N = "-.";
+    private static final String O = "---";
+    private static final String P = ".--.";
+    private static final String Q = "--.-";
+    private static final String R = ".-.";
+    private static final String S = "...";
+    private static final String T = "-";
+    private static final String U = "..-";
+    private static final String V = "...-";
+    private static final String W = ".--";
+    private static final String X = "-..-";
+    private static final String Y = "-.--";
+    private static final String Z = "--..";
+    private static final String ONE = ".----";
+    private static final String TWO = "..---";
+    private static final String THREE = "...--";
+    private static final String FOUR = "....-";
+    private static final String FIVE = ".....";
+    private static final String SIX = "-....";
+    private static final String SEVEN = "--...";
+    private static final String EIGHT = "---..";
+    private static final String NINE = "----.";
+    private static final String ZERO = "-----";
+    private static final String BREAK = "||";
+
+    private static final String morseAlphabet[] = new String[] {A, B, C, D, E, F, G, H, I, J, K, L,
+        M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, ONE, TWO, THREE, FOUR, FIVE, SIX,
+        SEVEN, EIGHT, NINE, ZERO, BREAK};
+    private static final StringBuilder englishAlphabet[] = new StringBuilder[] {
+            new StringBuilder("a"), new StringBuilder("b"), new StringBuilder("c"),
+            new StringBuilder("d"), new StringBuilder("e"), new StringBuilder("f"),
+            new StringBuilder("g"), new StringBuilder("h"), new StringBuilder("i"),
+            new StringBuilder("j"), new StringBuilder("k"), new StringBuilder("l"),
+            new StringBuilder("m"), new StringBuilder("n"), new StringBuilder("o"),
+            new StringBuilder("p"), new StringBuilder("q"), new StringBuilder("r"),
+            new StringBuilder("s"), new StringBuilder("t"), new StringBuilder("u"),
+            new StringBuilder("v"), new StringBuilder("w"), new StringBuilder("x"),
+            new StringBuilder("y"), new StringBuilder("z"), new StringBuilder("1"),
+            new StringBuilder("2"), new StringBuilder("3"), new StringBuilder("4"),
+            new StringBuilder("5"), new StringBuilder("6"), new StringBuilder("7"),
+            new StringBuilder("8"), new StringBuilder("9"), new StringBuilder("0"),
+            new StringBuilder(" ")
+    };
+
+    private static final Map <String,StringBuilder> morseToEnglish = new HashMap<>();
+
+    /* Constructor, initializes map for morse to english */
+    public Decoder(){
+        for(int i = 0; i < morseAlphabet.length; i++) { morseToEnglish.put(morseAlphabet[i], englishAlphabet[i]); }
+    }
+
+    /* Main method called by a Decoder object
+     * Is given a String from a line in a flat file, determines if it is valid morse code,
+     * Then calls other methods to decode and print english results
+    */
+    public void decodeText(String text){
+        MorseVerification verifyInput = new MorseVerification();
+        if(!verifyInput.isValid(text)){ System.out.println(text + " is not valid morse code"); return; }
+
+        System.out.println(getEnglishText(getMorseCharacters(text)));
+    }
+
+    /* Goes through the String of morse code character by character,
+     * determines when the end of a morse character has been reached, adds that character and a break character to
+     * A list of StringBuilder objects
+     * It returns that list once entire string as been parsed
+     */
+    private List<StringBuilder> getMorseCharacters(String text){
+        List<StringBuilder> fullMorseText = new ArrayList<>();
+        int characterCounter = 0;
+
+        while(characterCounter < text.length()) {
+
+            StringBuilder lastMorseCharacter = new StringBuilder();
+            StringBuilder currentMorseLetter = new StringBuilder();
+            String currentMorseCharacter = new String();
+            while (!lastMorseCharacter.append(currentMorseCharacter).toString().equals(BREAK) && characterCounter < text.length()) {
+                if(!currentMorseLetter.toString().equals("")){
+                    lastMorseCharacter =
+                        new StringBuilder(String.valueOf(currentMorseLetter.charAt(currentMorseLetter.length() - 1)));
+                }
+                currentMorseLetter.append(new StringBuilder(String.valueOf(text.charAt(characterCounter))));
+                currentMorseCharacter = String.valueOf(text.charAt(characterCounter));
+                characterCounter++;
+            }
+
+            if(!(characterCounter == text.length())){
+                if(!currentMorseLetter.toString().equals(BREAK)) {
+                    currentMorseLetter.delete(currentMorseLetter.length() - 2, currentMorseLetter.length());
+                    fullMorseText.add(currentMorseLetter);
+                }
+                fullMorseText.add(new StringBuilder(BREAK));
+            }
+            else{ fullMorseText.add(currentMorseLetter); }
+        }
+        return fullMorseText;
+    }
+
+    /* Is given a List of StringBuilder objects that are individual morse code characters,
+     * goes through and determines what break characters
+     * should be removed and which should remain to be interpreted as spaces in phrases
+     * then builds and returns that english String
+     */
+    private String getEnglishText(List<StringBuilder> morseText){
+        StringBuilder englishText = new StringBuilder();
+        StringBuilder previousChar, currentChar = new StringBuilder();
+
+        for(int i = 0; i < morseText.size(); i++){
+            previousChar = currentChar;
+            currentChar = morseText.get(i);
+            if(previousChar.toString().equals(BREAK) && currentChar.toString().equals(BREAK)){
+                morseText.remove(i);
+                currentChar = new StringBuilder();
+            }
+            else if (previousChar.toString().equals(BREAK) && !currentChar.toString().equals(BREAK)){
+                morseText.remove(i - 1);
+                i--;
+            }
+        }
+        for (StringBuilder aMorseText : morseText) { englishText.append(getNextEnglishCharacter(aMorseText)); }
+        return englishText.toString();
+    }
+
+    /* Method uses the morse character passed in to look up corresponding english character
+     * In the morse to english map, and returns that english character
+     */
+    private StringBuilder getNextEnglishCharacter(StringBuilder morseCharacter){
+       return morseToEnglish.get(morseCharacter.toString());
+    }
+}

kristoficSubmission/FileVerification.java

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+// Main class for determining if file given on command line is of valid format
+public class FileVerification {
+    private final String ACCEPTED_FILE_FORMAT = ".txt";
+
+    /* Constructor */
+    FileVerification(){}
+    /* Searches filename for valid extension
+     * returns true if valid extension is found, false if it is not found
+     */
+    public boolean isValid(String commandLineArgument){ return commandLineArgument.toLowerCase().contains(ACCEPTED_FILE_FORMAT); }
+}

kristoficSubmission/MorseDecoderMain.java

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+import java.io.*;
+
+/* Main driver class, should be compiled using javac MorseDecoderMain.java on the command line
+ * Then run using java MorseDecoderMain [filename]
+ */
+public class MorseDecoderMain {
+    public static void main(String[] args) throws IOException {
+
+        /* Checks to see if there are too many arguments */
+        if (args.length > 1) {System.out.println("There are too many arguments"); return;}
+        /* Instantiates FileVerification object and checks to see if command line file is a valid format */
+        FileVerification fileVerifier = new FileVerification();
+        if(!fileVerifier.isValid(args[0])){ System.out.println(args[0] + " is not an accepted file format. Please use .txt"); return; }
+
+        /* Instantiates Decoder object and parses file line by line to get morse phrases */
+        Decoder decoder = new Decoder();
+        File file = new File(args[0]);
+        BufferedReader br = new BufferedReader(new FileReader(file));
+        String st;
+        while((st = br.readLine()) != null){ decoder.decodeText(st);}
+    }
+}

kristoficSubmission/MorseVerification.java

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+// Main class that parses morse text to look for invalid characters
+public class MorseVerification {
+    /* Constructor */
+    MorseVerification() {}
+
+    /* Goes through morse string to look for invalid characters
+     * if an invalid character is detected returns false
+     * if no invalid character is detected, returns true
+     */
+    protected boolean isValid(String text){
+        for (int i = 0; i < text.length(); i++) {
+            if (text.isEmpty()) { return false; }
+            if(!((text.charAt(i) == '|') || (text.charAt(i) == '.') || (text.charAt(i) == '-'))) { return false; }
+            if(text.charAt(i) == '|' && i == 0) { return false; }
+            if(text.charAt(i) == '|' && i == (text.length() - 1)) { return false; }
+            if(i < text.length() - 1) {
+                if (text.charAt(i) == '|') {
+                    if(text.charAt(i - 1) == '|') {}
+                    else if (text.charAt( i + 1) == '|') {}
+                    else { return false; }
+                }
+            }
+        }
+        return true;
+    }
+}

kristoficSubmission/README.md

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+# softWritersInterviewDeliverable
+March 2019 Morse Decoder
+
+1) Compile through the command line using 'javac MorseDecoderMain.java'
+2) Run through the command line using 'java MorseDecoderMain [filename].txt'
+
+a sample .txt file has been provided, but is not required for use

kristoficSubmission/sample.txt

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+-..||---||--.
+....||.||.-..||.-..||---||||.--||---||.-.||.-..||-..
+-||....||.||||--.-||..-||..||-.-.||-.-||||-...||.-.||---||.--||-.||||..-.||---||-..-||||.---||..-||--||.--.||.||-..||||---||...-||.||.-.||||-||....||.||||.-..||.-||--..||-.--||||-..||---||--.
+THEN I SAW HER FACE
+|@.p-
+-..||---||--.|
+.-
+-...
+-.-.
+-..
+.
+..-.
+--.
+....
+..
+.---
+-.-
+.-..
+--
+-.
+---
+.--.
+--.-
+.-.
+...
+-
+..-
+..-
+.--
+-..-
+-.--
+--..
+.----
+..---
+...--
+....-
+.....
+-....
+--...
+---..
+----.
+-----