fs.cpp

#include <iostream>
#include <vector>
#include <stdio.h>
#include <string>
 
using namespace std;
 
struct Letter {
	char letter;
	string morse;
	int size;
 
	Letter(){}
	Letter(char c, string m) {
		letter = c;
		morse = m;
		size = m.size();
	}
};
 
enum {
	underscore = 26, 
	comma = 27, 
	period = 28, 
	question = 29
};
 
vector<Letter> dict;
 
void fillMorse();
string printMorse();
int getPosInDict(char c);
char getLetterByMorse(string str);
 
int main() {
 
	fillMorse();
	//printMorse();
 
	string line;
	while(cin >> line) {
		//cout << line << endl;
		string lineInMorse = "";
		int morseIntSize = line.size();
		int morseInt[morseIntSize];
		for(int i = 0; i < morseIntSize; i++) {
			int posInDict = getPosInDict(line[i]);
			lineInMorse += dict[posInDict].morse;
			morseInt[i] = dict[posInDict].size;			
		}
 
		/*
		cout << lineInMorse << endl;
		for(int i = 0; i < morseIntSize; i++) {
			cout << morseInt[i];
		}
		cout << endl;
		*/
 
		string decrypted = "";
		int morsePos = 0;
		for(int i = morseIntSize-1; i >= 0; i--) {
			string letterInMorse = lineInMorse.substr(morsePos, morseInt[i]);
			morsePos += morseInt[i];
			decrypted += getLetterByMorse(letterInMorse);
		}
		cout << decrypted << endl;
	}
 
	return 0;
}
 
void fillMorse() {
	dict.push_back(Letter('A', ".-"));
	dict.push_back(Letter('B', "-..."));
	dict.push_back(Letter('C', "-.-."));
	dict.push_back(Letter('D', "-.."));
	dict.push_back(Letter('E', "."));
	dict.push_back(Letter('F', "..-."));
	dict.push_back(Letter('G', "--."));
	dict.push_back(Letter('H', "...."));
	dict.push_back(Letter('I', ".."));
	dict.push_back(Letter('J', ".---"));
	dict.push_back(Letter('K', "-.-"));
	dict.push_back(Letter('L', ".-.."));
	dict.push_back(Letter('M', "--"));
	dict.push_back(Letter('N', "-."));
	dict.push_back(Letter('O', "---"));
	dict.push_back(Letter('P', ".--."));
	dict.push_back(Letter('Q', "--.-"));
	dict.push_back(Letter('R', ".-."));
	dict.push_back(Letter('S', "..."));
	dict.push_back(Letter('T', "-"));
	dict.push_back(Letter('U', "..-"));
	dict.push_back(Letter('V', "...-"));
	dict.push_back(Letter('W', ".--"));
	dict.push_back(Letter('X', "-..-"));
	dict.push_back(Letter('Y', "-.--"));
	dict.push_back(Letter('Z', "--.."));
	dict.push_back(Letter('_', "..--"));
	dict.push_back(Letter(',', ".-.-"));
	dict.push_back(Letter('.', "---."));
	dict.push_back(Letter('?', "----"));
}
 
string printMorse() {
	for(unsigned int i = 0; i < dict.size(); i++) {
		cout << dict[i].letter << " = " << dict[i].morse << endl;
	}
	return "";
}
 
int getPosInDict(char c) {
	if(c >= 'A' && c <= 'Z') {
		return c - 'A';
	} else {
		switch(c) {
		case '_': return underscore; 
		case ',': return comma; 
		case '.': return period; 
		case '?': return question; 
		default: return -1; 
		}
	}
}
 
char getLetterByMorse(string str) {
	for(unsigned int i = 0; i < dict.size(); i++) {
		if(dict[i].morse == str) {
			return dict[i].letter;
		}
	}
	return '%';
}