The Morse code (see Table 6.10 in book) is a common code that is used to encode messages consisted of letters and digits. Each letter consists of a series of dots and dashes; for example, the code for the letter a is *- and the code for the letter b is -***. Store each letter of the alphabet in a node of a binary tree of level 5. The root node is at level 1 and stores no letter. The left node at level 2 stores the letter e (code is *), and the right node stores letter t (code is -). The 4 nodes at level 3 store the letters with codes (**, *-, -*, --). To build the tree (see Figure 6.38 in book), read a file in which each line consists of a letter followed by its code. The letters should be ordered by tree level. To find the position for a letter in the tree, scan the code and branch left for a dot and branch right for a dash. Encode a message by replacing each letter by its code symbol. Then decode the message using the Morse code tree. Make sure you use a delimiter symbol between coded letters. Implementation Notes: You will need to complete the generic implementation of the BinaryTree data structure first (see slides). Once it is complete, solve the problem above (note that the book uses dots and dashes, we will use the asterisk (*) as the dot, hyphen (-) as a dash, and space ( ) as the delimiter symbol between coded letters). Provide a menu program that asks the user to 1) test output for all morse code letters with their respective translated alphabet letters (make sure you are using the binary tree to do the actual translation, output as a nicely formatted table), 2) enter an input file name to decode morse code and output the translated text to the screen, or 3) enter in a line of morse code through the console to decode morse code and output the translated text to the screen relevenat picture of both the tree diagram and the table of morse code Solution JAVA CODE: import java.io.*; import java.util.*; public class MorseCoder implements MorseCodeInterface { private MorseNode root; /** * constructor to build the tree */ public MorseCoder() { root = new MorseNode(); readTreeInfo(); } /** * reads in the tree info from the text file (helper method) */ private void readTreeInfo() { Scanner input = null; try { input = new Scanner(new File(\"encodings.txt\")); } catch (FileNotFoundException exception) { System.out.println(\"File not found!\"); } while (input.hasNextLine()) { String data = input.nextLine().trim(); if (data.length() > 0) { add(data.substring(1).trim(), data.charAt(0)); } } input.close(); } /** * adds the letter to the tree based on the mcode string (helper method) * @param mcode the string being fed in * @param ltr the letter being added at the node */ private void add(String mcode, char ltr) { MorseNode current = root; String signal = \" \"; for (int i = 0; i < mcode.length(); i++) { signal = mcode.substring(i, i + 1); if (signal.equals(\".\")) { if (current.getLeft() != null) { current = current.getLeft(); } else { current.set.

1. The Morse code (see Table 6.10 in book) is a common code that is used to encode messages
consisted of letters and digits. Each letter consists of a series of dots and dashes; for example, the
code for the letter a is *- and the code for the letter b is -***. Store each letter of the alphabet in a
node of a binary tree of level 5. The root node is at level 1 and stores no letter. The left node at
level 2 stores the letter e (code is *), and the right node stores letter t (code is -). The 4 nodes at
level 3 store the letters with codes (**, *-, -*, --). To build the tree (see Figure 6.38 in book),
read a file in which each line consists of a letter followed by its code. The letters should be
ordered by tree level. To find the position for a letter in the tree, scan the code and branch left for
a dot and branch right for a dash. Encode a message by replacing each letter by its code symbol.
Then decode the message using the Morse code tree. Make sure you use a delimiter symbol
between coded letters.
Implementation Notes: You will need to complete the generic implementation of the BinaryTree
data structure first (see slides). Once it is complete, solve the problem above (note that the book
uses dots and dashes, we will use the asterisk (*) as the dot, hyphen (-) as a dash, and space ( ) as
the delimiter symbol between coded letters). Provide a menu program that asks the user to 1) test
output for all morse code letters with their respective translated alphabet letters (make sure you
are using the binary tree to do the actual translation, output as a nicely formatted table), 2) enter
an input file name to decode morse code and output the translated text to the screen, or 3) enter
in a line of morse code through the console to decode morse code and output the translated text
to the screen
relevenat picture of both the tree diagram and the table of morse code
Solution
JAVA CODE:
import java.io.*;
import java.util.*;
public class MorseCoder implements MorseCodeInterface {
private MorseNode root;
/**
* constructor to build the tree
*/
public MorseCoder() {
root = new MorseNode();

2. readTreeInfo();
}
/**
* reads in the tree info from the text file (helper method)
*/
private void readTreeInfo() {
Scanner input = null;
try {
input = new Scanner(new File("encodings.txt"));
} catch (FileNotFoundException exception) {
System.out.println("File not found!");
}
while (input.hasNextLine()) {
String data = input.nextLine().trim();
if (data.length() > 0) {
add(data.substring(1).trim(), data.charAt(0));
}
}
input.close();
}
/**
* adds the letter to the tree based on the mcode string (helper method)
* @param mcode the string being fed in
* @param ltr the letter being added at the node
*/
private void add(String mcode, char ltr) {
MorseNode current = root;
String signal = " ";
for (int i = 0; i < mcode.length(); i++) {
signal = mcode.substring(i, i + 1);
if (signal.equals(".")) {
if (current.getLeft() != null) {
current = current.getLeft();
} else {
current.setLeft(new MorseNode());
current = current.getLeft();

3. }
} else {
if (current.getRight() != null) {
current = current.getRight();
} else {
current.setRight(new MorseNode());
current = current.getRight();
}
}
}
current.setLetter(ltr);
}
/**
* prints out inorder tree contents
*/
public void inOrderPrint() {
MorseNode current = root;
printInorder(current);
}
/**
* called by inOrderPrint to print tree contents (helper method)
* @param current the node to print
*/
private void printInorder(MorseNode current) {
if (current != null) {
printInorder(current.getLeft());
System.out.print(current.getLetter());
printInorder(current.getRight());
}
}
/**
* decodes a String of morse code to English
* @param str String of morse code
* @return result String of English
*/
public String decode(String str) {

4. String signal = "";
StringBuffer result = new StringBuffer("");
MorseNode current = root;
for (int i = 0; i < str.length(); i++) {
signal = str.substring(i, i + 1);
if (signal.equals(".")) {
if (current.getLeft() != null) {
current = current.getLeft();
} else {
current.setLeft(new MorseNode());
current = current.getLeft();
}
} else if (signal.equals("-")) {
if (current.getRight() != null) {
current = current.getRight();
} else {
current.setRight(new MorseNode());
current = current.getRight();
}
} else {
result = result.append(current.getLetter());
current = root;
}
}
result = result.append(current.getLetter());
return result.toString();
}
/**
* decodes a String of English to morse code
* @param str String of English
* @return result String of morse code
*/
public String encode(String str) {
MorseNode current = root;
String result = "";

5. String s = "";
char ltr;
for (int i = 0; i < str.length(); i++) {
ltr = str.charAt(i);
result = searchTree(current, ltr, s);
}
return result;
}
/**
* searches the tree for the letter(s) being inputed and outputs a string of morse (helper
method)
* @param current the node of the tree
* @param ltr the letter being searched for in the tree
* @param s the String being used to build the morse code
* @return the morse code corresponding to the item being checked
*/
public String searchTree(MorseNode current, char ltr, String s) {
char temp = current.getLetter(); //for debugging purposes
if (current.getLetter() == ltr) {
return s;
} else {
if (current.getLeft() != null) {
return searchTree(current.getLeft(), ltr, s + ".");
}
if (current.getRight() != null) {
return searchTree(current.getRight(), ltr, s + "-");
}
return s;
}
}
}
/*Interface*/
public interface MorseCodeInterface {
void inOrderPrint();
String decode(String str);

6. String encode(String str);
}
/**
* Node class to use with morsecode tree. Do not modify this class.
*/
public class MorseNode {
/** a letter of the alphabet */
private char letter;
/** reference to the left child */
private MorseNode left;
/** reference to the right child */
private MorseNode right;
/** value of letter if empty (not set) */
public static final char EMPTY = ' ';
/*** Default constructor, actual values are set in the MorseCode constructor*/
public MorseNode() {
letter = EMPTY;
left = null;
right = null;
}
/**
* Gets letter contained in node
* @return String - letter value
*/
public char getLetter() {
return letter;
}
/**
* Sets letter in node
* @param String - letter to set
*/
public void setLetter(char letter) {
this.letter = letter;
}
/**
* Gets the node refrenced by left

7. * @return MorseNode - left
*/
public MorseNode getLeft() {
return left;
}
/**
* Sets left refrence
* @param left - refrence to the node to set
*/
public void setLeft(MorseNode left) {
this.left = left;
}
/**
* Gets the node refrenced by right
* @return MorseNode - right
*/
public MorseNode getRight() {
return right;
}
/**
* Sets right refrence
* @param right - refrence to the node to set
*/
public void setRight(MorseNode right) {
this.right = right;
}}
public class MorseMain {
public static void main(String[] args) {
//Do not modify this file.
MorseCoder mc = new MorseCoder();
mc.inOrderPrint();
// sos decode
System.out.println("Decode Test 1");
String str = "... --- ...";
System.out.println("str = " + str);
System.out.println("str should decode to: sos");

8. System.out.println("decode(str) = " + mc.decode(str));
testResults("sos", mc.decode(str));
// abcdef...xyz decode
System.out.println("Decode Test 2");
str = ".- -... -.-. -.. . ..-. --. .... .. .--- -.- .-.. -- -."
+ " --- .--. --.- .-. ... - ..- ...- .-- -..- -.-- --..";
System.out.println("str = " + str);
System.out.println("str should decode to: abcdefghijklmnopqrstuvwxyz");
System.out.println("decode(str) = " + mc.decode(str));
testResults("abcdefghijklmnopqrstuvwxyz", mc.decode(str));
// helpmeobiwanyouremyonlyhope decode
System.out.println("Decode Test 3");
str = ".... . .-.. .--. -- . --- -... .. .-- .- -. -.-- --- ..-"
+ " .-. . -- -.-- --- -. .-.. -.-- .... --- .--. .";
System.out.println("str = " + str);
System.out.println("str should decode to: helpmeobiwanyouremyonlyhope");
System.out.println("decode(str) = " + mc.decode(str));
testResults("helpmeobiwanyouremyonlyhope", mc.decode(str));
// --.. encode
System.out.println("Encode Test 1");
str = "z";
System.out.println("str = " + str);
System.out.println("str should encode to: --..");
System.out.println("encode(str) = " + mc.encode(str));
testResults("--..", mc.encode(str));
// ... --- ... encode
System.out.println("Encode Test 2");
str = "sos";
System.out.println("str = " + str);
System.out.println("str should encode to: ... --- ...");
System.out.println("encode(str) = " + mc.encode(str));
testResults("... --- ...", mc.encode(str));

9. // .-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -. encode
System.out.println("Encode Test 3");
str = "runforrestrun";
System.out.println("str = " + str);
System.out.println("str should encode to: .-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -.");
System.out.println("encode(str) = " + mc.encode(str));
testResults(".-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -.", mc.encode(str));
}
/**
* Tests if the output string matches the expected.
* Prints "Test: Passed" if they match, otherwise prints "Test: Failed"
* @param one String - Expected output
* @param two String - Encoded/Decoded call
*/
public static void testResults(String one, String two) {
if(one.trim().equals(two.trim()))
System.out.println("Test: Passed");
else
System.out.println("Test: Failed");
System.out.println();
}
}
INPUT:
encodings.txt :
a .-
b -...
c -.-.
d -..
e .
f ..-.
g --.
h ....
i ..

10. j .---
k -.-
l .-..
m --
n -.
o ---
p .--.
q --.-
r .-.
s ...
t -
u ..-
v ...-
w .--
x -..-
y -.--
z --..
OUTPUT:
Sample output:
h
s
v
i
f
u
e
l
r
a
p
w
j
b

11. d
x
n
c
k
y
t
z
g
q
m
o
Decode Test 1
str = ... --- ...
str should decode to: sos
decode(str) = sos
Test: Passed
Decode Test 2
str = .- -... -.-. -.. . ..-. --. .... .. .--- -.- .-.. -- -. --- .--. --.- .-. ... - ..- ...- .-- -..- -.-- --..
str should decode to: abcdefghijklmnopqrstuvwxyz
decode(str) = abcdefghijklmnopqrstuvwxyz
Test: Passed
Decode Test 3
str = .... . .-.. .--. -- . --- -... .. .-- .- -. -.-- --- ..- .-. . -- -.-- --- -. .-.. -.-- .... --- .--. .
str should decode to: helpmeobiwanyouremyonlyhope
decode(str) = helpmeobiwanyouremyonlyhope
Test: Passed
Encode Test 1
str = z
str should encode to: --..
encode(str) = --..
Test: Passed
Encode Test 2
str = sos

12. str should encode to: ... --- ...
encode(str) = ... --- ...
Test: Passed
Encode Test 3
str = runforrestrun
str should encode to: .-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -.
encode(str) = .-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -.
Test: Passed
/**
* Node class to use with morsecode tree. Do not modify this class.
*/
public class MorseNode {
/** a letter of the alphabet */
private char letter;
/** reference to the left child */
private MorseNode left;
/** reference to the right child */
private MorseNode right;
/** value of letter if empty (not set) */
public static final char EMPTY = ' ';
/*** Default constructor, actual values are set in the MorseCode constructor*/
public MorseNode() {
letter = EMPTY;
left = null;
right = null;
}
/**
* Gets letter contained in node
* @return String - letter value
*/
public char getLetter() {
return letter;
}
/**
* Sets letter in node
* @param String - letter to set

13. */
public void setLetter(char letter) {
this.letter = letter;
}
/**
* Gets the node refrenced by left
* @return MorseNode - left
*/
public MorseNode getLeft() {
return left;
}
/**
* Sets left refrence
* @param left - refrence to the node to set
*/
public void setLeft(MorseNode left) {
this.left = left;
}
/**
* Gets the node refrenced by right
* @return MorseNode - right
*/
public MorseNode getRight() {
return right;
}
/**
* Sets right refrence
* @param right - refrence to the node to set
*/
public void setRight(MorseNode right) {
this.right = right;
}}
public class MorseMain {
public static void main(String[] args) {
//Do not modify this file.
MorseCoder mc = new MorseCoder();

14. mc.inOrderPrint();
// sos decode
System.out.println("Decode Test 1");
String str = "... --- ...";
System.out.println("str = " + str);
System.out.println("str should decode to: sos");
System.out.println("decode(str) = " + mc.decode(str));
testResults("sos", mc.decode(str));
// abcdef...xyz decode
System.out.println("Decode Test 2");
str = ".- -... -.-. -.. . ..-. --. .... .. .--- -.- .-.. -- -."
+ " --- .--. --.- .-. ... - ..- ...- .-- -..- -.-- --..";
System.out.println("str = " + str);
System.out.println("str should decode to: abcdefghijklmnopqrstuvwxyz");
System.out.println("decode(str) = " + mc.decode(str));
testResults("abcdefghijklmnopqrstuvwxyz", mc.decode(str));
// helpmeobiwanyouremyonlyhope decode
System.out.println("Decode Test 3");
str = ".... . .-.. .--. -- . --- -... .. .-- .- -. -.-- --- ..-"
+ " .-. . -- -.-- --- -. .-.. -.-- .... --- .--. .";
System.out.println("str = " + str);
System.out.println("str should decode to: helpmeobiwanyouremyonlyhope");
System.out.println("decode(str) = " + mc.decode(str));
testResults("helpmeobiwanyouremyonlyhope", mc.decode(str));
// --.. encode
System.out.println("Encode Test 1");
str = "z";
System.out.println("str = " + str);
System.out.println("str should encode to: --..");
System.out.println("encode(str) = " + mc.encode(str));
testResults("--..", mc.encode(str));
// ... --- ... encode

15. System.out.println("Encode Test 2");
str = "sos";
System.out.println("str = " + str);
System.out.println("str should encode to: ... --- ...");
System.out.println("encode(str) = " + mc.encode(str));
testResults("... --- ...", mc.encode(str));
// .-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -. encode
System.out.println("Encode Test 3");
str = "runforrestrun";
System.out.println("str = " + str);
System.out.println("str should encode to: .-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -.");
System.out.println("encode(str) = " + mc.encode(str));
testResults(".-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -.", mc.encode(str));
}
/**
* Tests if the output string matches the expected.
* Prints "Test: Passed" if they match, otherwise prints "Test: Failed"
* @param one String - Expected output
* @param two String - Encoded/Decoded call
*/
public static void testResults(String one, String two) {
if(one.trim().equals(two.trim()))
System.out.println("Test: Passed");
else
System.out.println("Test: Failed");
System.out.println();
}
}
INPUT:
encodings.txt :
a .-
b -...
c -.-.

16. d -..
e .
f ..-.
g --.
h ....
i ..
j .---
k -.-
l .-..
m --
n -.
o ---
p .--.
q --.-
r .-.
s ...
t -
u ..-
v ...-
w .--
x -..-
y -.--
z --..
OUTPUT:
Sample output:
h
s
v
i
f
u
e
l
r

17. a
p
w
j
b
d
x
n
c
k
y
t
z
g
q
m
o
Decode Test 1
str = ... --- ...
str should decode to: sos
decode(str) = sos
Test: Passed
Decode Test 2
str = .- -... -.-. -.. . ..-. --. .... .. .--- -.- .-.. -- -. --- .--. --.- .-. ... - ..- ...- .-- -..- -.-- --..
str should decode to: abcdefghijklmnopqrstuvwxyz
decode(str) = abcdefghijklmnopqrstuvwxyz
Test: Passed
Decode Test 3
str = .... . .-.. .--. -- . --- -... .. .-- .- -. -.-- --- ..- .-. . -- -.-- --- -. .-.. -.-- .... --- .--. .
str should decode to: helpmeobiwanyouremyonlyhope
decode(str) = helpmeobiwanyouremyonlyhope
Test: Passed
Encode Test 1

18. str = z
str should encode to: --..
encode(str) = --..
Test: Passed
Encode Test 2
str = sos
str should encode to: ... --- ...
encode(str) = ... --- ...
Test: Passed
Encode Test 3
str = runforrestrun
str should encode to: .-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -.
encode(str) = .-. ..- -. ..-. --- .-. .-. . ... - .-. ..- -.
Test: Passed