Huffman 05

void createCharData(Map<ext_char, string> &data, Node* head, string result) {
	if (head -> one == NULL && head -> zero == NULL) {
		data.put(head -> character, result);
	}
	if (head -> one != NULL) {
		result = result + "1";
		createCharData(data, head -> one, result);
	}
	if (head -> zero != NULL) {
		result = result + "0";
		createCharData(data, head -> zero, result);
	}
}


/* Function: encodeFile
* Usage: encodeFile(source, encodingTree, output);
* --------------------------------------------------------
* Encodes the given file using the encoding specified by the
* given encoding tree, then writes the result one bit at a
* time to the specified output file.
*
* This function can assume the following:
*
*   - The encoding tree was constructed from the given file,
*     so every character appears somewhere in the encoding
*     tree.
*
*   - The output file already has the encoding table written
*     to it, and the file cursor is at the end of the file.
*     This means that you should just start writing the bits
*     without seeking the file anywhere.
*/
void encodeFile(istream& infile, Node* encodingTree, obstream& outfile) {
	Map<ext_char, string> data;
	string result = "";
	createCharData(data, encodingTree, result);
	char ch;
	while(true){
		if(infile.fail()) break;
		ch = infile.get();
		string str = data.get(ch);
		for (int i = 0; i < str.length(); i++) {
			if (str[i] == '0')
				outfile.writeBit(0);
			else
				outfile.writeBit(1);
		}
	}
	string tmp = data.get(PSEUDO_EOF);
	for (int i = 0; i < tmp.length(); i++) {
		if (tmp[i] == '0')
			outfile.writeBit(0);
		else
			outfile.writeBit(1);
	}
}