1. Binary Search Trees II
Morse Code

2. An Application: Morse Code Table
Let's create a BST to translate ASCII characters into Morse Code symbols.
Use genBST1.h template.
Will create a new class to be the template parameter.
New empty C++ project
ASCII_to_Morse_Code

3. Initial main.cpp #include <iostream> using namespace std;
int main() {
cout << "Enter an ASCII string to be translated into Morse Code\n";
char buffer[1000];
cin.getline(buffer, 1000);
cout << "You entered:\n";
cout << buffer;
cin.get();
return 0; }

4. Initial Program Running

5. Class Morse_Code_Pair
Add class Morse_Code_Pair
Each object will specify the Morse Code symbol for one ASCII character.
We will build a BST of these objects.
Use the BST to translate ASCII into Morse Code.
Copy source files from:

6. Morse_Code_Pair.h #pragma once #include <iostream>
#include <string>
class Morse_Code_Pair {
public:
std::string symbol; // A Morse code symbol.
char value; // The letter or digit represented
// by this symbol
// Default constructor
Morse_Code_Pair();
// Normal constructor
Morse_Code_Pair(std::string symbol_, char value_);
// Accessor functions
std::string get_symbol() const {return symbol; }
char get_value() const {return value; } };

7. Morse_Code_Pair.h // Less than operator
bool operator<(const Morse_Code_Pair& lhs,
const Morse_Code_Pair& rhs);
// Equals operator
bool operator==(const Morse_Code_Pair& lhs,
// Output operator
std::ostream& operator<<(std::ostream& out,
const Morse_Code_Pair& s);

8. Morse_Code_Pair.cpp #include "Morse_Code_Pair.h" using namespace std;
// Default constructor
Morse_Code_Pair::Morse_Code_Pair() : symbol("", ' ') {}
// Normal constructor
Morse_Code_Pair::Morse_Code_Pair(string symbol_, char value_) :
symbol(symbol_), value(value_)
// Less then operator
bool operator< (const Morse_Code_Pair& lhs,
const Morse_Code_Pair& rhs) {
char c_lhs = lhs.get_value();
char c_rhs = rhs.get_value();
return c_lhs < c_rhs; }

9. Morse_Code_Pair.cpp // Equals operator
bool operator==(const Morse_Code_Pair& lhs,
const Morse_Code_Pair& rhs) {
char c_lhs = lhs.get_value();
char c_rhs = rhs.get_value();
return c_lhs == c_rhs; }

10. Morse_Code_Pair.cpp ostream& operator<<(ostream& out,
const Morse_Code_Pair& s) {
string symbol_string = s.get_symbol();
for (size_t i = 0; i < symbol_string.length(); ++i)
if (symbol_string[i] == '_')
symbol_string[i] = '-'; }
out << s.get_value() << " " << symbol_string;
return out;

11. main.cpp #include <iostream> #include "genBST1.h"
#include "Morse_Code_Pair.h"
using namespace std;
// Conservative upper bound on length of a single Morse code symbol
const int MAX_SYMBOL_LEN = 10;
// Binary Search Tree to map Morse code symbols to characters
BST<Morse_Code_Pair> morse_map;
void add_symbol_to_map(string symbol, char value) {
Morse_Code_Pair sym(symbol, value);
morse_map.insert(sym); }

12. build_map In main.cpp: void build_map() {
add_symbol_to_map("....", 'H');
add_symbol_to_map("___..", '8');
add_symbol_to_map("._.", 'R');
add_symbol_to_map("...__", '3');
add_symbol_to_map("_._.", 'C');
add_symbol_to_map("__", 'M');
add_symbol_to_map("..._", 'V');
add_symbol_to_map(".____", '1');
add_symbol_to_map(".....", '5');
add_symbol_to_map("._", 'A');
add_symbol_to_map(".", 'E');
add_symbol_to_map(".___", 'J');
add_symbol_to_map("___", 'O');
add_symbol_to_map("_", 'T');
add_symbol_to_map("_.._", 'X');
add_symbol_to_map(".__", 'W');

13. build_map add_symbol_to_map("_____", '0');
add_symbol_to_map("_...", 'B');
add_symbol_to_map("_..", 'D');
add_symbol_to_map(".._.", 'F');
add_symbol_to_map("..", 'I');
add_symbol_to_map("_._", 'K');
add_symbol_to_map(".__.", 'P');
add_symbol_to_map("_.__", 'Y');
add_symbol_to_map("__...", '7');
add_symbol_to_map("__.", 'G');
add_symbol_to_map("._..", 'L');
add_symbol_to_map("_.", 'N');
add_symbol_to_map("__._", 'Q');
add_symbol_to_map("...", 'S');
add_symbol_to_map(".._", 'U');
add_symbol_to_map("__..", 'Z'); }

14. main.cpp
int main() {
build_map();
morse_map.display(cout);

15. The Morse_Pair BST

16. main.cpp Add at end of main.cpp:
cout << "\n\nHere is the string in Morse Code:\n";
for (int i = 0; i < (int) strlen(buffer); ++i) {
char c = toupper(buffer[i]);
Morse_Code_Pair* search_target = new Morse_Code_Pair("", c);
Morse_Code_Pair* mcp = morse_map.search(*search_target);
if (mcp == 0)
cout << " "; }
else
string next_symbol = mcp->get_symbol();
cout << next_symbol << " ";
cout << endl;

17. Program in Action
End of Presentation