coding mastermind in C, only got 2 probs..

hi all,

i'm trying to code mastermind (textbased) in C, but i stumble into two problems..

here is the code:

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>


int main()
{
        srand( (unsigned)time( NULL ) );
        int play_or_instruct;
        int get_random;
        int max_tries;
        int get_answer;
        int print_answer;
        int count_equal;
        int count;
        int correct;
        int secret_code[5];
        int answer[5];
        printf("\nWelcome to mastermind.\n");
        printf("press 1 to play, press 2 for instructions :");
        scanf("%d",&play_or_instruct);
        if (play_or_instruct==2)                /*check for playing the game or instructions*/
        { 
                printf("\n\nThe goal of the game is to guess the secret\n");
                printf("secret code. You have 10 tries for this.\n");
                printf("The code contains 5 random numbers from 0 - 9.\n");
                printf("Every \'*\' you see next to your input, \n");
                printf("means that you have one number correct and\n");
                printf("at the right place.\n");
                printf("Every \'0\' you see next to your input,\n");
                printf("means that you have one number correct, but\n");
                printf("not at the right place.\n");
                play_or_instruct=1;
        }
        if (play_or_instruct ==1)
        {
                printf("\nHere we go....\n\n");
               
                for (get_random = 0; get_random <5; get_random++) /*get the secret code with the*/
                            secret_code[get_random] = rand()%10;        /*random function*/
                for(max_tries=0;max_tries<10;max_tries++)        /*count number of tries*/
                {
                        printf("\nEnter your guess: ");
                        for(get_answer=0;get_answer<=4;get_answer++)/*get the answer given*/
                        {
                                scanf("%d",&answer[get_answer]);
                        printf("\n");
                        }
                        for(print_answer=0;print_answer<=4;print_answer++)/*print the answer*/
                                printf("%d",answer[print_answer]);/*given to the screen*/
                        printf("\t");
                        for(count_equal=0;count_equal<=4;count_equal++)        /*check if a number is*/
                        {                                        /*correct and at the right place*/
                                if(answer[count_equal]==secret_code[count_equal])
                                        printf("*");  /*print * if correct*/
                               
                        }
                        count=0;
                        for(correct=0;correct<=4;correct++)/*check if the complete code is */
                        {                                        /*correct, for each digit*/
                                if(answer[correct]==secret_code[correct])/*count + 1*/
                                        count++;
                        }
                        if(count==5)/*if count is equal to 5, let them know they've won, and*/
                        {                        /*end the game.*/
                                printf("\nCongratulations, you've won!\n");
                                return 0;
                        }
                       
                }
                if(max_tries==10)/*if maximum number of tries have passed, let them know*/
                {                        /*they didn't made it and end the game*/
                        printf("\nUnfortunately you did not make it.\n");
                        return 0;
                }
        }
       
}
/*only got two problems,
1st problem:
getting to print a '0' for each character that is present, but not at the right place, and don't print it double if one character is compaired to two.
2nd problem:
as the code is now, the user has to press <enter> after each digit they enter, this has to change. e.g. when entering 12345, it now is 1<enter>2<enter>3<enter>4<enter>5<enter>.*/

---

the problems i mean are:

1st problem:
getting to print a '0' for each character that is present, but not at the right place, and don't print it double if one character is compaired to two.
2nd problem:
as the code is now, the user has to press <enter> after each digit they enter, this has to change. e.g. when entering 12345, it now is 1<enter>2<enter>3<enter>4<enter>5<enter>.

if anyone knows how i can solve these problems, and tell it to me of course :D, that would be highly appreciated..

>>the user has to press <enter> after each digit they enter, this has to change
You mean like this:
http://faq.cprogramming.com/cgi-bin/...&id=1043284392

Move the srand() call to after the variable definitions, its not allowed where you've put it, unless your using C99 or C++.

Don't forget to return 0; at the end of main().

if it is not allowed, the srand(), then how come it worked? i compiled it on gcc and on dev-c++, on gcc i used the command "gcc -o mastermind mastermind.c" so i didn't use it as c++.

but i will change it to below the variables to avoid problems in the future...

as for the return 0;
it is already inserted in the code at the points i needed it, i see no use putting return 0; at the end of main, since the code will never come to that point... (no offense by the way)

Quote:

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>>the user has to press <enter> after each digit they enter, this has to change
You mean like this:
http://faq.cprogramming.com/cgi-bin...6&id=1043284392

---

this is not what i meant, what i mean is:
since answer[] is declared as an integer, it can take more then 0-9 as value, and since this is the only input i need for this program, i will have to press <enter> after each digit entered... this would be easy if answer[] would be a char, since then you can use the functions getch() or getchar() since these only and maximally require one keystroke (one byte), so at the next keystroke, the character is automatically put in the next place in the array. This i also want to achieve with the integer, but like i said, i haven't got the slightest clue on how to solve this...

hope this makes things clear...

>>then how come it worked?
Because your compiler was kind to you. Mine wasn't, and neither would yours be if you up the warning levels:

Code:

---

$ gcc -Wall -pedantic junk1.c
junk1.c: In function `main':
junk1.c:9: warning: ISO C89 forbids mixed declarations and code
junk1.c:78: warning: control reaches end of non-void function

---

>>so at the next keystroke, the character is automatically put in the next place in the array
Read the input as a string instead of an int, then process it in memory.

>>return 0;
Follow the logic of your code, you'll see that things can happen that cause you to bypass all of your existing return statements.

ok, learned something new about the srand() function :)
as for the return 0; i still don't get it, but i'll go and study it even more...

how would i process a string in memory?
never heared of that before...

about the return 0;

i have always been taught that in each function that there should be one entry and one exit point. some people might choose to object to this but i think it is good coding practice. but return 0; being at the end of your main function, symbolises the end of your program. unless an error has occurred, your program should only exit at that single exit point. :)

Quote:

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i have always been taught that in each function that there should be one entry and one exit point. some people might choose to object to this but i think it is good coding practice. but return 0; being at the end of your main function, symbolises the end of your program. unless an error has occurred, your program should only exit at that single exit point.

---

that i do get, but as far as i can see in my above code, the program always runs into a return 0; if no error occurs, so i didn't saw the need to put it in the end of main.
but let's just forget about the return 0; , it's just one line, it doesn't matter to me to put it in it...

(b.t.w., in my other programs which do end normal, i do use return 0;)

For the first question, I've always kept an array of booleans with my array of secret digits so that I can check them off as they are used.

Code:

---

for (i = 0; i < 5; i++)
  check[i] = false;

for (i = 0; i < 5; i++)
{
  if (guess[i] == secret[i])
  {
      correctplace++;
      check[i] = true;
  }
}

for (i = 0; i < 5; i++)
{
  for (j = 0; j < 5; j++)
  {
      if ((guess[i] == secret[j]) && (check[j] == false))
      {
        correctdigit++;
        check[j] = true;
      }
  }
}

---

For the second question, you could input all five numbers at the same time into an int and then extract them using modular arithmetic. Something like:

Code:

---

if ((input_number > 9999) && (input_number < 100000))  //bounds checking
{
  for (int i = 0; i < 5; i++)
  {
      guess[i] = input_number % 10;
      input_number /= 10;
  }
}

---

The only problem with doing it this way is that leading zeroes won't work.

Quote:

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Originally Posted by lepricaun

that i do get, but as far as i can see in my above code, the program always runs into a return 0; if no error occurs, so i didn't saw the need to put it in the end of main.
but let's just forget about the return 0; , it's just one line, it doesn't matter to me to put it in it...

(b.t.w., in my other programs which do end normal, i do use return 0;)

---

It should matter to you if you wish to become a programmer. Here's the reason:
main() is an int -- always. It is not a void, not a float. Only int. Therefore, you need to start the program with

Code:

---

int main()

---

You see, main is a function. It is called by the operating system (definition is good enough for this explanation). As you are probably aware, in C every function must be defined as returning a type and having a return t; at the end or a void and a return; at the end (which is optional for void only). You get to define what and how all your own functions return -- but you must always use them that way. You can't return a float from an int function.

Well since main is a function, it is defined by the operating system as returning an int. It therefore must return an int. Period. That's the way it was designed.

So, your signature code:

Code:

---

#include <stdio.h>

main()
{
printf("Hello world!");
}

---

is all wrong. It really should be:

Code:

---

#include <stdio.h>

int main()    // an int definition
{
    printf("Hello world!");    // indent for readability
    return 0;    // give the OS the int it is looking for
}

---

WaltP>> i understand what you mean, but try this site, it has a bunch of C tutorials and most of them start out without declaring main() as an int, like my signature...

i understand that the OS should get a resonse back from a program to know if it ended as it should, or ended with a exitcode 1 or something like that, so i know what it is meant for, but as you can see in my code above, it has return 0; in it, just not at the lowest bottom of main(), but they are there...

pianorain>>thanks for your answer, i'll go and see if i can get it to work :)

i'll let you know..

Quote:

---

Originally Posted by lepricaun

WaltP>> i understand what you mean, but try this site, it has a bunch of C tutorials and most of them start out without declaring main() as an int, like my signature...

i understand that the OS should get a resonse back from a program to know if it ended as it should, or ended with a exitcode 1 or something like that, so i know what it is meant for, but as you can see in my code above, it has return 0; in it, just not at the lowest bottom of main(), but they are there...

---

An implicit int (that is to say, if the return type int was not explicitly added to the code, the compiler would assume an int return type) used to be legal - I believe that is why on older code you could write main() without specifiying what type it was. That is no longer true. You must give the return type. And yes we see your code has a few return statements - Did you see what Hammer mentioned about that though? Look:

Don't forget to return 0; at the end of main()

and

Follow the logic of your code, you'll see that things can happen that cause you to bypass all of your existing return statements.

If your return statement is at the end of main(), it will get used at some point, provided your program does not crash. The way you have things set up, it is not guaranteed that they will be used.

~/

Quote:

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If your return statement is at the end of main(), it will get used at some point, provided your program does not crash. The way you have things set up, it is not guaranteed that they will be used.

---

hence what i said about having one exit point

Quote:

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Originally Posted by lepricaun.sig

Code:

---

#include <stdio.h>

main()
{
printf("Hello world!");
}

---

---

This is plain wrong.

C90 : the 'int' is not required, but an explicit return value is.
C99 : the 'int' is required, but an explicit return value is not.

In both cases, the emitted characters are not terminated by a '\n'. The result may appear or not on the display device. Add a '\n', of force the output (fflush(stdout)).

You may upgrade your .sig the portable way:

Code:

---

#include <stdio.h>

int main (void)
{
  printf ("Hello world!\n");
  return 0;
}

---

well, it's just a sig, but if it is bothering you guys i'll change it :)

as for the program, i did what pianorain suggested and got to this code:

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define false 0
#define true 1


int main()
{
        srand( (unsigned)time( NULL ) );
        int play_or_instruct;
        int get_random;
        int max_tries;
        int get_answer;
        int print_answer;
        int count_equal;
        int correctplace=0;
        int run,a;
        int correctdigit=0;
        int secret_code[5];
        int answer[5];
        int check[5];
        printf("\nWelcome to mastermind.\n");
        printf("press 1 to play, press 2 for instructions :");
        scanf("%d",&play_or_instruct);
        if (play_or_instruct==2)                /*check for playing the game or instructions*/
        { 
                printf("\n\nThe goal of the game is to guess the secret\n");
                printf("secret code. You have 10 tries for this.\n");
                printf("The code contains 5 random numbers from 0 - 9.\n");
                printf("Every \'*\' you see next to your input, \n");
                printf("means that you have one number correct and\n");
                printf("at the right place.\n");
                printf("Every \'0\' you see next to your input,\n");
                printf("means that you have one number correct, but\n");
                printf("not at the right place.\n");
                play_or_instruct=1;
        }
        if (play_or_instruct ==1)
        {
                printf("\nHere we go....\n\n");
               
                for (get_random = 0; get_random <5; get_random++) /*get the secret code with the*/
                            secret_code[get_random] = rand()%10;        /*random function*/
                for(max_tries=0;max_tries<=10;max_tries++)        /*count number of tries*/
                {
                        printf("\nEnter your guess: ");
                        for(get_answer=0;get_answer<=4;get_answer++)/*get the answer given*/
                        {
                                scanf("%d",&answer[get_answer]);
                        }
                        printf("\n");
                        for(print_answer=0;print_answer<=4;print_answer++)/*print the answer*/
                                printf("%d",answer[print_answer]);/*given to the screen*/
                        printf("\t");
                        check[get_answer] = false;
                        for (get_answer = 0; get_answer < 5; get_answer++)
                        {
                                  if (answer[get_answer] == secret_code[get_answer])
                                  {
                                              correctplace++;
                                              check[get_answer] = true;
                                  }
                        }
                               
                        for (get_answer = 0; get_answer < 5; get_answer++)
                        {
                          for (run = 0; run < 5; run++)
                          {
                              if ((answer[get_answer] == secret_code[run]) && (check[run] == false))
                              {
                                correctdigit++;
                                check[run] = true;
                              }
                          }
                        }
                        if(correctplace ==5)
                        {
                                printf("\nCongratulations, you've won!\n");
                                return 0;
                        }
                        for(;correctplace >=0;correctplace--)
                                printf("*");
                        for(;correctdigit >=0;correctdigit--)
                                printf("0");
                        printf("\n");
                        if(max_tries==10)/*if maximum number of tries have passed, let them know*/
                        {                        /*they didn't made it and end the game*/
                                printf("\nUnfortunately you did not make it.\n");
                                return 0;
                        }
                }
        }
        return 0;
}

---

(watch the return 0 ; :))
but somehow it looks to work fine, but when you play the program and recalculate, it just isn't right...

any hints??

the logic in your game is pretty messy (although it could be a lot worse) try creating functions to simplify the flow of your program.