#include <iostream>
#include <cctype>

using namespace std;

string generateSoundex(string st);
string convertToUpperCase(string st);

int main (int argc, char * const argv[]) {
	string word1, word2;
	string soundex1, soundex2;
	
	cout << "\n\nNew Horizons Governors School Team B\n";
	cout << "Enter the first word: ";
	cin >> word1;
	cout << "Enter the second word: ";
	cin >> word2;
	
	word1 = convertToUpperCase(word1);
	word2 = convertToUpperCase(word2);
	
	soundex1 = generateSoundex(word1);
	soundex2 = generateSoundex(word2);
	
	int comparison = soundex1.compare(soundex2);
	int commonPrefix = 0;
	
	for (int i = 0; i < soundex1.length() && i < soundex2.length(); i++) {
		if (soundex1[i] == soundex2[i])
			commonPrefix++;
		else
			break;
	}
	
	cout << "\nSoundex of " << word1 << " is " << soundex1 << endl;
	cout << "Soundex of " << word2 << " is " << soundex2 << endl;
	if (comparison == 0)
		cout << "They have the same encoding" << endl;
	else
		cout << "They do not have the same encoding" << endl;
	
	cout << "They share a common prefix of " << commonPrefix << endl;
	
    return 0;
}

string generateSoundex(string st) {
	string soundex = st;
	
	//discard vowels and vowel-like letters
	for (int i = soundex.length() - 1; i >= 1; i--) {
		switch (soundex[i]) {
			case 'A':
			case 'E':
			case 'I':
			case 'O':
			case 'U':
			case 'H':
			case 'W':
			case 'Y':
				soundex.erase(i, 1);
				break;
		}
	}
	
	//map letters to digits
	for (int i = 1; i < soundex.length(); i++) {
		switch (soundex[i]) {
			case 'B':
			case 'P':
				soundex[i] = '1';
				break;
			case 'F':
			case 'V':
				soundex[i] = '2';
				break;
			case 'C':
			case 'K':
			case 'S':
				soundex[i] = '3';
				break;
			case 'G':
			case 'J':
				soundex[i] = '4';
				break;
			case 'Q':
			case 'X':
			case 'Z':
				soundex[i] = '5';
				break;
			case 'D':
			case 'T':
				soundex[i] = '6';
				break;
			case 'L':
				soundex[i] = '7';
				break;
			case 'M':
			case 'N':
				soundex[i] = '8';
				break;
			case 'R':
				soundex[i] = '9';
				break;
		}
	}
	
	//discard duplicates
	for (int i = soundex.length() - 1; i > 1; i--) {
		if (soundex[i] == soundex[i - 1])
			soundex.erase(i, 1);
	}
	
	//and add the initial character
	st.insert(0, st.substr(0, 1));
	return soundex;
}

string convertToUpperCase(string st) {
	for (int i = 0; i < st.length(); i++)
		st[i] = toupper(st[i]);
	return st;
}