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If statements

arcticman452 (14)
I am not able to get my if statements to output the correct number. Here is the code I have so far

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 #include <iostream>
    #include <sstream>
    #include <string>
    #include <ctime>
    #include <cmath>
    #include <math.h>
    #include <algorithm>

    using namespace std;

    void Welcome_Screen()
    {
		cout << "You are playing the text version of Mastermind." << endl << endl;
		cout << "The rules are to guess the 5 digit number before your number of guesses run out. " << endl << endl;
		cout << "The numbers run from 1 - 9 and there can be multiple numbers of the same number." << endl << endl;
		cout << "1 implies the right number in the right place." << endl;
		cout << "2 implies the right number but in the wrong place." << endl;
		cout << "0 implies wrong number." << endl << endl;
		cout << "Ready?? Here we go." << endl << endl;

		system("pause");
		system("cls");
    }

    string convert_int_to_string(int computer_number[5])
    {
		stringstream computer_numbers[5];
		computer_numbers[0] << computer_number[0];
		computer_numbers[1] << computer_number[1];
		computer_numbers[2] << computer_number[2];
		computer_numbers[3] << computer_number[3];
		computer_numbers[4] << computer_number[4];
		return computer_numbers[5].str();
    };

    string convert_player_guess_int_to_string(int player_guess[5])
    {
		stringstream player_numbers[5];
		player_numbers[0] << player_guess[0];
		player_numbers[1] << player_guess[1];
		player_numbers[2] << player_guess[2];
		player_numbers[3] << player_guess[3];
		player_numbers[4] << player_guess[4];
		return player_numbers[5].str();
    };

    int main()
    {
		Welcome_Screen();

		srand(static_cast<unsigned int>(time(0)));

		int computer_number[5], player_guess[5], guess_code[5];
		int random_number1 = rand() % 6 + 1;
		int random_number2 = rand() % 6 + 1;
		int random_number3 = rand() % 6 + 1;
		int random_number4 = rand() % 6 + 1;
		int random_number5 = rand() % 6 + 1;

		computer_number[0] = random_number1;
		computer_number[1] = random_number2;
		computer_number[2] = random_number3;
		computer_number[3] = random_number4;
		computer_number[4] = random_number5;

		int number_of_guesses = 12;

		cout << "The computer has made it's choices and set it's 5 numbers down. " << endl << endl;
		cout << "What are your number guesses? (press enter after each number)" << endl << endl;

		for(int a = 0; a < number_of_guesses; ++a)
		{

			cout << "Guess 1: ";
			cin >> player_guess[0];
			cout << endl;

			cout << "Guess 2: ";
			cin >> player_guess[1];
			cout << endl;

			cout << "Guess 3: ";
			cin >> player_guess[2];
			cout << endl;

			cout << "Guess 4: ";
			cin >> player_guess[3];
			cout << endl;

			cout << "Guess 5: ";
			cin >> player_guess[4];
			cout << endl << endl;

			//Checks first guess
			if( computer_number[0] == player_guess[0] )
			{
				guess_code[0] = 1;
			}

			else if(computer_number[0] != player_guess[0]|| player_guess[1] || player_guess[2] || player_guess[3] || player_guess[4])
			{
				guess_code[0] = 0;
			}

			else(computer_number[0] == player_guess[1] || player_guess[2] || player_guess[3] || player_guess[4]);
			{
				guess_code[0] = 2;
			}

			//Checks second guess
			if( computer_number[1] == player_guess[1] )
			{
				guess_code[1] = 1;
			}

			if(computer_number[1] != player_guess[0]|| player_guess[1] || player_guess[2] || player_guess[3] || player_guess[4])
			{
				guess_code[1] = 0;
			}

			if(computer_number[1] == player_guess[0] || player_guess[2] || player_guess[3] || player_guess[4])
			{
				guess_code[1] = 2;
			}

			//Checks third guess
			if( computer_number[2] == player_guess[2] )
			{
				guess_code[2] = 1;
			}

			if(computer_number[2] != player_guess[0]|| player_guess[1] || player_guess[2] || player_guess[3] || player_guess[4])
			{
				guess_code[2] = 0;
			}

			if(computer_number[2] == player_guess[0] || player_guess[1] || player_guess[3] || player_guess[4])
			{
				guess_code[2] = 2;
			}

			//Checks forth guess
			if( computer_number[3] == player_guess[3] )
			{
				guess_code[3] = 1;
			}

			if(computer_number[3] != player_guess[0]|| player_guess[1] || player_guess[2] || player_guess[3] || player_guess[4])
			{
				guess_code[3] = 0;
			}

			if(computer_number[3] == player_guess[0] || player_guess[1] || player_guess[2] || player_guess[4])
			{
				guess_code[3] = 2;
			}

			//Checks fifth guess
			if( computer_number[4] == player_guess[4] )
			{
				guess_code[4] = 1;
			}

			if(computer_number[4] != player_guess[0]|| player_guess[1] || player_guess[2] || player_guess[3] || player_guess[4])
			{
				guess_code[4] = 0;
			}

			if(computer_number[4] == player_guess[0] || player_guess[1] || player_guess[2] || player_guess[3])
			{
				guess_code[4] = 2;
			}

			cout <<"Here is the outcome of guess number "<< a <<":\n";

			for (unsigned int i=0; i < 5; i++)
			{
				cout << computer_number[i]<<"   ";
			}

			cout <<endl;


			for (unsigned int i=0; i < 5; i++)
			{
				cout << player_guess[i]<<"   ";
			}

			cout << endl;

			for (unsigned int i=0; i < 5; i++)
			{
				cout << guess_code[i] <<"   ";
			}

			cout <<endl;
			
			

		}

   
		system("pause");
		return 0;
    }
Disch (13742)
if(computer_number[2] == player_guess[0] || player_guess[1] || player_guess[3] || player_guess[4])

|| does not work like you think it does. For some reason this is a common mistake with beginners.

|| looks at both the left and ride side of it. If either side is nonzero (true), the result is nonzero (true). Otherwise the result is zero (false). The || operator is unaware that the left side of it is a == operation, and therefore does not give you multiple right-hand values for the == operator. It merely combines the output of the == operator with another expression.

EXAMPLE:

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int foo = 5;
if(foo == 1 || 2)
{
  // this if statement will ALWAYS run
}


Notice the if block will run, even though foo does not equal 1 or 2. That's because the compiler interprets this as follows:

(foo == 1 || 2) // start with this

-) look at foo==1. foo contains 5, so this results in false.

(false || 2) // evaluates to this

-) look at '2'. This is nonzero, so it gets interpretted as 'true'

(false || true) // evaluates to this

-) The || operator compares what's on each side of it. Since the right side of it is true, it evaluates to true

(true) // finally evaluates to this

-) Since it gets evaluated to true, the if block executes.



What you probably wanted to do was this:

 
 
if(foo == 1 || foo == 2)


But I don't doing that because it makes you code get ugly and out of control really fast. A better solution would be to move some of these checks inside a loop... or inside separate functions.
Last edited on
arcticman452 (14)
So would this work
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 //Checks first guess
if( computer_number[0] == player_guess[0] )
{
    guess_code[0] = 1;
}

for (int i = 0; i<5; i++)
{
    if(computer_number[0] == player_guess[i])
    {
        guess_code[0] = 0;
    }

    else  guess_code[0] = 2;
}
Disch (13742)
Close. The problem there is that player_guess[0] through [3] will be effectively ignored because player_guess[4] will always determine the final value of guess_code[0]. The else clause in the for loop is the culprit there.

Something like this might work:

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guess_code[0] = 0; // by default, assume they did not guess correctly

if( computer_number[0] == player_guess[0] )
  guess_code[0] = 1;  // if they guessed correctly, change that to give them the '1' code

for(int i = 1; i < 5; ++i)  // note I start at 1, not zero
{
  if( computer_number[0] == player_guess[i] )  // if they guessed it on any non-first guess
    guess_code[0] = 2;  // revise to give them the '2' code
}


Of course, I would also throw all of this in a function so you don't have to copy/paste it a million times.
arcticman452 (14)
I haven't done a lot of work with functions but to make this a function I'm thinking I would have to do something like this

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void Check_Guess()

guess_code[0] = 0; // by default, assume they did not guess correctly

if( computer_number[0] == player_guess[0] )
  guess_code[0] = 1;  // if they guessed correctly, change that to give them the '1' code

for(int i = 1; i < 5; ++i)  // note I start at 1, not zero
{
  if( computer_number[0] == player_guess[i] )  // if they guessed it on any non-first guess
    guess_code[0] = 2;  // revise to give them the '2' code
}


Then once I have this built, would I call it after every time the player makes a guess and what would I need to do so the array position, guess_code[0] change to guess_code[1]?
Disch (13742)
You only want to keep the logic in the function. The actual variables will be passed to/from the function. This makes it more reusable.

Here, you have 2 things that you want to input to the function:
1) The computer's number
2) The players guesses

And you have one thing you want to output:
1) The guess code.

Typically when there's only one output, you 'return' that value. So the function would look something like this:

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int Check_Guess( int correct_answer, int player_guess[], int guess_count )
{
  //...
}


Here, you would check each entry in the 'player_guess' array (of which you know you have 'guess_count' entries) against the 'correct_answer'. Depending on if/when they guessed the number correctly, you will return the appropriate guess code.

Usage would be like this:

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guess_code[0] = Check_Guess( computer_number[0], player_guess, 5 );

// or... if you want to loop it:
for(int i = 0; i < 5; ++i)
  guess_code[i] = Check_Guess( computer_number[i], player_guess, 5 );
arcticman452 (14)
I think I understand what you are trying to do here. I will play with it and see if I can make it work. The only question I do have is do I need a return statement somewhere?
Disch (13742)
If your function is going to be outputting data via it's return value, then yes you will need a return statement in the function.

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