TripleX Random Number Generator

[Frank]

So I have completed my TripleX Game but I don’t like the random numbers generator proposed during the course. Main reason is that when we fail a level the values change opening an opportunity to cheat the game by constantly failing in order to get easier questions. I’ve already changed the rng a bit by expanding the range of the numbers ( Adding difficulty level to difficulty level ) since I felt like its a bit too easy and I wondered if maybe i can solve this ‘cheating problem’ by creating a function that would act like an on/off switch for seeding the rand using real time, which makes the numbers actually random. And here lies the problem. I don’t know if such an operation of enabling and disabling srand is actually possible. I would be happy to hear any thoughts you have about my code, the presentation of it etc.
(Sorry bout the poor image quality. I was testing out the Polacode)

[DanM]

That’s incredibly narrow and hard to read.

@Frank

like an on/off switch for seeding the rand using real time, which makes the numbers actually random.

What do you mean by this?

[Frank]

Like a way to stop the numbers from randomising if the player fails the level so the numbers in this particular level would stay the same.

[DanM]

You don’t need to mess with rand. Just put a loop in the PlayGame function if the guess isn’t correct.

[Frank]

So I tried putting a while loop inside my PlayGame but I’m encountering an error “Control may reach end of non-void function” and I’m not really sure how to fix it. Could you explain why this error shows ?

[DanM]

So there’s actually two cases of undefined behaviour (UB) here. You have the following

int GuessA, GuessB, GuessC;

These variables are uninitialised and hold indeterminate values. Reading of interdeminate values is UB which is what you do on the following two lines.

non-void functions must return a value. In the while condition if CodeSum == GuessSum and CodeProd == GuessProd- which whilst unlikely, is still a non-zero chance since UB has already been invoked - then this function doesn’t reach any of the return statements so the function wouldn’t return a value and would also invoke UB.

---

If you fix the first issue by moving them after you get values for A,B,C then that would still cause a problem. Whilst we can logicially see that’s impossible it’s still required that all control paths can return a value. So you can fix this by having a return statement after the while loop.

---

You’re going to run into another issue but here are some (hopefully) helpful info.

• Return statements return from the function i.e. exit them. If they get it wrong are you going to get the result you’re after?
• Maybe you want something else for the condition like lives? Or an infinite loop might be useful?
• There’s a do-while loop which is the same as a while loop but instead it checks at the end of the loop instead of the start of it. The syntax is

  do
  {
     //code
  } while(condition);
  

[Frank]

With the help of my father, who is a programmer, I fixed the while loop issue and we came up with the same idea of having the return statement after the while loop. Unfortunately this created another problem since I want to include lives into the game and having no return false statement makes it a bit hard. Also the fact that C++ does not have just an ‘or’ statement (as is one or the other must be correct or wrong) complicates things a lot for me. Here is what I’ve got so far. I feel like I’m making my life unnecessarily hard with some of this code. On my own I implemented the do while loop as you suggested earlier.

[Frank]

Update on what I’ve got so far. I’ve managed to implement working lives counter into my game but at the expense of allowing the numbers to randomise after failing a level. Still haven’t figured out how to make both of them work

[DanM]

Well you had a good go but this is one way to do it

bool PlayGame(int Difficulty)
{
	PrintIntroduction(Difficulty);

	// Generate Code
	const int CodeA = rand() % Difficulty + Difficulty;
	const int CodeB = rand() % Difficulty + Difficulty;
	const int CodeC = rand() % Difficulty + Difficulty;

	const int CodeSum = CodeA + CodeB + CodeC;
	const int CodeProduct = CodeA * CodeB * CodeC;


	// Print CodeSum and CodeProduct to the terminal
	std::cout << "+ There are 3 numbers in the code";
	std::cout << "\n+ The codes add-up to: " << CodeSum;
	std::cout << "\n+ The codes multiply to give: " << CodeProduct << std::endl;

	int Lives = 5;
	do
	{
		// Store player guess
		int GuessA, GuessB, GuessC;
		std::cin >> GuessA >> GuessB >> GuessC;

		const int GuessSum = GuessA + GuessB + GuessC;
		const int GuessProduct = GuessA * GuessB * GuessC;

		// Check if the players guess is correct
		if (GuessSum == CodeSum && GuessProduct == CodeProduct)
		{
			std::cout << "\n*** Well done agent! You have extracted a file! Keep going! ***";
			return true;
		}
		else
		{
			std::cout << "\n*** You entered the wrong code! Careful agent! Try again! ***";
			std::cout << "\n*** You have " << --Lives  << " remaining ***\n";
		}

	} while (Lives > 0);
	return false;
}

If you want the lives to persist then you would need to pass that into the function.