Help with recursion { recursive helper function }

Can you please help me with the source code solving this task under C++/G++ (linux) or dev C++ (windows)

http://mail.dir.bg/~storage/cPlus_plus111.jpg

Below you can see a hint for solving Exercise P14.1 but I need to write the source for Exercise P14.1 Please help me

http://www.horstmann.com/bigcpp/solu...14/ExP14_1.cpp

Code:

---

#include <string>

using namespace std;

/**
  Reverse a sentence.
*/
class Sentence
{
public:
  /**
      Creates a Sentence object.
      @param aPhrase a sentence to reverse.
  */
  Sentence(string aPhrase);
 
  /**
      Reverses this sentence.
      @return the reversed sentence
  */
  string reverse();
   
private:
  string phrase;
};

Sentence::Sentence(string aPhrase) 
{
  phrase = aPhrase;
}

 
string Sentence::reverse()
{
  if (phrase != "")
  {
      string c = phrase.substr(0, 1);
      string rest = phrase.substr(1, phrase.length() - 1);
      Sentence tailSentence(rest);
      phrase = tailSentence.reverse() + c;
  }
  return phrase;
}

int main()
{
  Sentence greeting("Hello!");
  cout << greeting.reverse() << "\n";
  return 0;
}

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We don't do homework. Try on your own and come back if you have more specific questions.

okay here is what I did is it the source okay ?

Code:

---

#include <string>
#include <iostream>
using namespace std;

/**
  Reverse a sentence.
*/
class Sentence
{
public:
  /**
      Creates a Sentence object.
      @param aPhrase a sentence to reverse.
  */
  Sentence(string aPhrase);
 
  /**
      Reverses this sentence.
      @return the reversed sentence
  */
  string reverse();
  string reverseSubstring(int beginning,int end);
   
private:
  string phrase;
};

Sentence::Sentence(string aPhrase) 
{
  phrase = aPhrase;
}

 
string Sentence::reverse()
{
  if (phrase != "")
  {
      string c = phrase.substr(0, 1);
      string rest = phrase.substr(1, phrase.length() - 1);
      Sentence tailSentence(rest);
      phrase = tailSentence.reverse() + c;
  }
  return phrase;
}
string Sentence::reverseSubstring(int beginning,int end)
{
  if (phrase != "")
  {
      string sBegining = phrase.substr(0, beginning - 1);
      string sEnd = phrase.substr(end,phrase.length()-1);
      Sentence toReverse(phrase.substr(beginning -1,end - 1));
      toReverse.reverse();
      phrase = sBegining + toReverse.phrase + sEnd;
  }
  return phrase;
}

int main()
{
  Sentence greeting("Hello!");
  //cout << greeting.reverse() << "\n";
  cout << greeting.reverseSubstring(2,4) << "\n";
  return 0;
}

---