Can't solve this Number Guessing Game problem

[shiding]

I've bought this book 'Beginning C++ through game programming' and it told me how to make a number guessing game, then it challenged me to make a number guessing game where the computer guesses my number. I've been at it for 2 hours, but I can't seem to solve this one problem.
You can say if the number is higher or lower than the number guessed by the computer or spot on. But what I wanted to do is create an exit for when the person just keeps pressing 'higher' or 'lower' so the computer tells them that it is their number because it can't go higher or lower anymore.
I'll post all the code so you can get the whole picture, I'll also place a row of comments above my problem.
This would be the first interactive program I've made, so any tips would be welcome

//This here is for the forum, "stdafx.h" is something I have to use because of the compiler i'm using, MS visual studio express 2012
#include "stdafx.h"
#include <iostream>
#include <ctime>
#include <cstdlib>
#include <string>
using namespace std;

int main (){


int gameMode;
int playerGuess, computerGuess, previousGuess;
int higherThan, lowerThan;
int tries;
int secretNumber;
char guessRight;
char playAgain;

cout
<< "Welcome to the number guessing game!\n\n";

gameLoop:

cout
<< "Would you like to:\n"
<< "0. Stop\n"
<< "1. Guess a number\n"
<< "2. Have the computer guess a number\n\n"

<< "I would like to: ";
cin >> gameMode;
cout << endl << endl;

playerGuess = 0;
computerGuess= 0;
tries = 0;
// Resetting the guess and amount of tries in case of replay

srand(static_cast<unsigned int>(time(0)));
// Seeding the number generator for both game modes

if (gameMode == 0)
{
	return 0;
}

else if (gameMode == 1)
{
	secretNumber = (rand() % 100) + 1;

	cout << "The number can range between 1 and 100\n";

	do
	{
		cout << "Guess my number: ";
		cin >> playerGuess;
		++tries;

		if (playerGuess < secretNumber)
		{
			cout << "Nope, higher!";
		}
		
		else if (playerGuess > secretNumber)
		{
			cout << "Nope, lower!";
		}
		
		else
		{
			if (tries == 1)
			{
				cout << "You guessed it in 1 try, well done!!";
			}

			else
			{
				cout << "You guessed it in " << tries << " tries.";
			}
			
			cout << "\n\nWould you like to play again? (y/n): ";
			cin >> playAgain;

			if (playAgain == 'y')
			{
				cout << "\n\n\n";
				goto gameLoop;
			}

			else
			{
				return 0;
			}
		}
		cout << endl << endl;

	} while (playerGuess != secretNumber);
}


else if (gameMode == 2)
{
	computerGuess = (rand() % 100) + 1;
	previousGuess = 0;
	higherThan = 0;
	lowerThan = 101;
	// resetting all computer's guessing values in case of replay
//PROBLEM!!PROBLEM!!PROBLEM!!PROBLEM!!PROBLEM!!PROBLEM!!PROBLEM
//My problem is below this text, What i'm trying to do is that when
//the player keeps saying 'h' or 'l' while they said it's higher than say, 74
//but also say it's lower than 74, the program says, "no you're screwing with me, it's 74".
//but I can't get it to work, the most important keywords are 'computerGuess' and 'previousGuess'
//
//
//
//
	do
	{
		cout
		<< "My guess is: " << computerGuess << endl
		<< "is it higher, lower or just right? (h/l/r): ";
		cin >> guessRight;
		cout << endl << endl;

		if (guessRight == 'h')
		{
			previousGuess = computerGuess;
			higherThan = computerGuess;
			computerGuess = rand() % (lowerThan - higherThan) + higherThan +1;
			
			if (computerGuess == previousGuess)
			{
				cout << "you're just fucking with me, it is " << computerGuess;
				guessRight = 'r';
			}
			
			else if (computerGuess == lowerThan)
			{
				--computerGuess;
			}
			
			else {}

		}

		else if (guessRight == 'l')
		{ 
			previousGuess = computerGuess;
			lowerThan = computerGuess;
			computerGuess = rand() % (lowerThan - higherThan) + higherThan +1;
			
			if (computerGuess == previousGuess)
			{
				cout << "You're just fucking with me, it's " << computerGuess;
				guessRight = 'r';
			}
		} 

		else
		{
			if (tries == 1)
			{
				cout << "Ha, that was easy!";
			}
		}

	} while (guessRight != 'r');

	cout << "\n\nWould you like to play again? (y/n): ";
	cin >> playAgain;

		if (playAgain == 'y')
		{
			cout << "\n\n\n";
			goto gameLoop;
		}

		else
		{
			return 0;
		}
}

else
{
	cout << "Please enter a valid option.\n\n\n";
	goto gameLoop;
}
	return 0;
}

[Stormboy]

Well I'd make the computer guess like this:
(Perhaps you can pick ideas from here?)

#include <iostream>
#include <cstdlib>
#include <time.h>
#include <string>

int main()
{
    srand(static_cast<unsigned int>(time(NULL))); //Set the random seed
    int secret_number = 0;

    std::cout << "You will make the computer guess your number!" << std::endl;
    std::cout << "Type in 'r' if computer is right, 'h' if the guess is too low, 'l' if guess if too high.\n" << std::endl;
    std::cout << "Enter the secret number (only b/w you and me): ";
    std::cin >> secret_number;

    int rounds = 1;
    int guess = rand() % secret_number+1;
    std::string you = "z";
    while(true)
    {
        std::cout << "\nYou: The number is somewhere between 0 and " << secret_number+100 << std::endl;
        while(!(you == "r" || you == "l" || you == "h"))
        {
            std::cout << "\nComputer: My guess is " << guess << ". \n" << std::endl;
            std::cout << "Is it right [r/h/l]: ";
            std::cin >> you;
            if(!(you == "r" || you == "l" || you == "h"))
                std::cout << "\nComputer: ME NO UNDERSTAND WHT U SAY!! Y U NO CLEAR!?\n" << std::endl;
        }

        if(you == "r")
        {
            if(guess != secret_number)
                std::cout << "\nComputer: I get the strange feeling that you are lying. BUT it doesn't matter." << std::endl;
            std::cout << "\nComputer: Le me le boss!" << std::endl;
            break;
        }
        else if(you == "h")
        {
            if(guess == secret_number)
            {
                std::cout << "\nComputer: You are a liar!" << std::endl;
                break;
            }
            std::cout << "\nComputer: Damn..OK I'll try again." << std::endl;
            guess += rand() %16;
        }
        else if(you == "l")
        {
            if(guess == secret_number)
            {
                std::cout << "\nComputer: You are a liar!" << std::endl;
                break;
            }
            std::cout << "\nComputer: Damn..OK I'll try again." << std::endl;
            guess -= rand() %16;
        }
        you = "z";
        rounds++;
    }

    std::cout << "\nComputer took " << rounds << " rounds to guess right." << std::endl;

    std::cin.get();
    std::cin.ignore();

    return 0;
}

[SorinAlex]

Here maybe this helps you :

#include <iostream>

using namespace std;

int main()
{
    int lower,higher,maxnr,answer,myguess;
    cout<<"Think of a number between 1 and ";cin>>maxnr;
    higher=maxnr+1;lower=1;
    while(true){
    myguess=(higher+lower)/2;
    cout<<"I think it is "<<myguess<<'\n';
    cout<<"Is this the number ?\n";
    cout<<"1.Lower\n";
    cout<<"2.This is it !\n";
    cout<<"3.Higher\n";
    cin>>answer;
    if(answer==1) higher=myguess;
    if(answer==2) {cout<<"It was fun wasn't it\n"; return 0;}
    if(answer==3) lower=myguess;}
    return 0;
}

[SorinAlex]

Heres my other try.Now it detects the number that is left:

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
void pause()
{
    //Prevents the application from exiting imediatly ...
    cout<<endl<<"Press any key to continue . . .";
    cin.ignore();
    cin.get();
}
int main()
{
    int maxnumber,minnumber=1,answer,number,aux;
    srand(time(0));
    cout<<"Think of a number between 1 and ";cin>>maxnumber;
    ++maxnumber;
    while(answer!=2){
    aux=maxnumber-minnumber;
    if(aux){
    number=rand()%aux+minnumber;}
    else {cout<<"You cheated !\n"; pause(); return 0;}
    cout<<"I think it is "<<number<<endl;
    cout<<"It is this the number ?\n\n";
    cout<<"1.Less\n";
    cout<<"2.This is it!\n";
    cout<<"3.Higher\n\n";
    cin>>answer;cout<<endl;
    if(answer==1) {
    maxnumber=number;
    }
    if(answer==3){
    minnumber=number+1;
    }
    if(maxnumber-1==minnumber) {cout<<"I found your number.It is "<<minnumber<<endl; pause(); return 0;}
    }
    pause();
    return 0;
}