HELP with coding.....

hello everyone...I'm still learning c...I had to create a porgram to calculate the number of possible selections of choosing R players from N. I have use the facotorial function..I have done the coding..there is till one error in it..If someone could help..plzzzz

Code:

---

void main()
{
        int n,r;
        long int selection;
        int factorial();

        printf("\n Enter the N-number of players:");
        scanf("%",&n);
        printf("\n Enter the R-number of players you wish to select from %d players:",n);
        scanf("%d",&r);

        selection= (factorial(n))/ ((factorial(r))*(factorial(n-r)));

        printf("\n The number of possible selections of %d players from %d players is %d",r,n,selection);




}

int factorial(int x)

{
        if (n<1)
                return(1);
        else
                return(n*factorial(n-1));

}

---

Describe the problem a bit better, please...

Is it compiling but not running, running but not giving correct result, or not even compiling? If it's running with the wrong result, what are the data you enter?

--
Mats

> scanf("%",&n);
Are you forgetting something here?

Also main returns int, not void.

thanks for ur quick replies..ooops for the small errorss...

Well I needed to kno if the way I treatred the question was well...

If this way i would get the answer correctly...

when I run it for the first time..after entering data for n..the compiler doesnt ask for entering R but goes directly to the answer..????

n in

Code:

---

}

int factorial(int x)

{
        if (n<1)
                return(1);
        else
                return(n*factorial(n-1));

}

---

is said to be undefined....

Until you fix the first scanf, I can't see it doing anything but skip reading n.

> is said to be undefined....
Your parameter is x, yet you use n.

thanks..i spoted my mistake....

Oh GOD............Its working.....................


I managed to run it successfully....


in int factorial[int x] should have been int factorial[int n]


Thanks guys...sorrry for disturbing ya........ Thanks agai

If u guys dont mind... can I ask another question plzzzzzzzzzzzzz???? Its concerning another program... I just really cant understand how perform this condition...

It says ask a question.. if answer is right pass to next...if it is wrong repeat question..if again wrong then give right answer.....


what condition loop may i use??? If else, While, for or do..??? Plzz helpp

You can, realisticly, perform that as a for, while or do-while loop. The most natural choice is perhaps a for-loop, because you have a set number of "iterations" (two) that you should perform the task. But any of the loops can do this.

You could also do it using if/else, but that would repeat the same bit of code, which for the purpose of this excercise seems "wrong".

--
Mats

You don't need a loop for that at all. You just needed an if-else statement with another if-else statement nest in its else clause.

Quote:

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Originally Posted by Happy_Reaper

You don't need a loop for that at all. You just needed an if-else statement with another if-else statement nest in its else clause.

---

Yes, but that's not "teaching how to use loops" - which I have a feeling is what the excercise is about - I could be wrong, it could be about "nested if-statements", in which case your solution is right - but this solution is very inflexible - if you want to ask 3 times, 4 times or 5 times, you need to (noticably) change the code. A loop solution is very easy to change the number of iterations that it does.

--
Mats

hmmmmmmmmmmmmmmmmmmmmmmmm.......well can any one write up abit of the code..I'll still cant get that in my head...
P.s Do I need a counter here????

hmmm Guys...I'll give it a try...If Im still messed up..I'll get the coding here for u to help..

Once again thanks a lot..dunno what I would have done If this forum wasnt here...

Yes, you will need SOME way of counting how many times you've done it - unless you build the "count" into the code as Happy_reaper suggests.

I'd rather that you TRY to write something, post it here, and then we'll discuss how to "improve" and "fix" it. That way, you do the learning, we do the correcting - rather than you only learning "that if you ask someone else to do it, you get something".

Of course, I could write something that you would get zero points for by your teacher - even if it works... Would you rather that I posted that?

--
Mats

ur right.....I'll try my best to start the coding a bit..n post it here..If ever Im completely stucK..please bear with me..Im still a newbie in this....

Sure, and I wil give HINTS to solutions, but part of learning to program is to learn how to "think" in terms of "how to solve problems using a computer". And that's not always that easy.

Giving you the right solution directly is not going to help you.

--
Mats

I have tried a few lines of coding...dunno if im right.....please anyone cheK it out...

Code:

---

void main()
{
        int count;
        char ans[6];

        printf("\n Welcome to the QuiZ Competition....R u READY????");


        for (count=1; count<3; ++count)

        {
                printf("\n What is the date of birth of Gandhi?");
                scanf("&#37;s",&ans);
                if (ans=02.10.69)
                        break;
        }

        {
                printf("\n The answer u stupid is 02.10.69");
        }
        }

---

Good start. I would probably start the loop with 0 - that's the traditional way to do loops.

Also, you just loop around asking, not checking if the answer is right (and breaking the loop when this happens).

Edit: And, if you expect the user to actually input "02.10.69", you may want to have a string longer than 6 chars - consider that:
there are 6 positions for the date itself, then two dots, and all strings also need a "ending zero". So you are at least 3 short.

--
Mats

you cannot simply put

ans=02.10.69

first because of the == vs = and second because 02.10.69 is a string "02.10.69"
if you want to compare string:

#include <string.h>
....

if(strcmp(ans,"02.10.69")==0) break;

ok...thanks..I'll try that..But still Im having an error to compile that..
At:
The "if" statement in the loop....

Quote:

---

Originally Posted by shaheel

ok...thanks..I'll try that..But still Im having an error to compile that..
At:
The "if" statement in the loop....

---

can you repost the code?

It also helps if you post the EXACT error message from the compiler. It can be hard to spot some subtle errors without the information of what the compiler says.

--
Mats

here is the new coding...no errors..no warnings...:

Code:

---

#include <string.h>
#include <stdio.h>
void main()
{
        int count;
        char ans[9];

        printf("\n Welcome to the QuiZ Competition....R u READY????");


        for (count=1; count<3; ++count)

        {
                printf("\n What is the date of birth of Gandhi?");
                scanf("&#37;s",&ans);
                if(strcmp(ans,"02.10.69")==0) break;

                else printf("\n The answer u stupid is 02.10.69");
        }

        {
                printf("\n Fabulous worK..Ur Great...");
        }
        }

---

I know it is upsetting... but trying to rewrite the same program with "while loop" could be useful...

That looks about right. What's not working is that you don't say "bravo" when the user gets it right - and perhaps you want to say "try again" when the user gets it wrong.
And you don't really need the braces around the answer - but if you want to say "stupid" then you probably should only print it when the answer is wrong.

You can solve most of the "do this" or "don't do this" by adding a variable to say "correct" or "not correct", e.g "correcAnswer = 0" to begin with, and if you get a correct answer, set "correctAnswer = 1". Then when the loop ends [for whatever cause] you check the variable "correctAnswer" to see if it was correct or not.

--
Mats

well..I'll try to put ur advices in practice.... I was about to ask this very much..if there could be a way to store the corect answerrs in a particular function and another function where the score of the user may be calculated.....

Quote:

---

Originally Posted by shaheel

here is the new coding...no errors..no warnings...:

---

doesn't your compiler give you a warning about return type of 'main' ? It should be int...

To add on to what matsp advised: change void main() to int main(), then include a return 0; statement at the end of main() if you are not compiling with respect to the C99 standard.

Also, I believe you should actually use:

Code:

---

scanf("%s", ans);

---

Quote:

---

Originally Posted by shaheel

well..I'll try to put ur advices in practice.... I was about to ask this very much..if there could be a way to store the corect answerrs in a particular function and another function where the score of the user may be calculated.....

---

You could write a function to ask a question and compare it to a correct answer. And you could also either call this function from another function that sums up the number of right answers, or call a function that updates a score for the person when the answer is right. Or something like that.

--
Mats

Quote:

---

Originally Posted by shaheel

well..I'll try to put ur advices in practice.... I was about to ask this very much..if there could be a way to store the corect answerrs in a particular function and another function where the score of the user may be calculated.....

---

the "score" of the user is the variable "count" (maybe +1 if loop start from zero.) what do you mean for store the corect answerrs in a particular function ?

I corrected the void main thing....

from the way Ive started..will it b possible for me to implement a type of variable to store the number of good answers..coz this is not the only question..I have to ask 10 questions in all...

And total the final score..........Im feeeling stucKk.........dnt know what to do nexT..