Thread: please ....i need help with this program

For some reason I have a feeling that you have just dumped your homework to us. It smells like your teacher had given the code to you, and asked you to complete it. I doubt that you would've written that if your goal is what you described. Students tend to start by writing a main, not by trying to implement a list...

So please, tell us more specifically waht your problem is. Simple "help me to write a program" does not quite cut it...

you are thinking this too complicated...

think it this way... for every "(" there has to be a ")" otherwise the expression is wrong...

why all this pushing and poping and use of struct? unless you are simulating push-down automata

Originally Posted by creeping death

you are thinking this too complicated...

think it this way... for every "(" there has to be a ")" otherwise the expression is wrong...

why all this pushing and poping and use of struct? unless you are simulating push-down automata

So this expression is correct then:

Code:

())(()

since it contains the right number of left and right match.

--
Mats

No! if my "flag" variable if it becomes -1, the expression is wrong(it becomes -1 and does not check any further)...hehe...you almost got me on that occasion

Code:

[c_d@localhost c scratchpad]$ ./a.out
enter expression())(()
expr is wrong

like i said earlier for every "(" there got to be a ")" ... since ")" came before "(" the expression became wrong...

hi angel_copra,

Code:

printf("please enter your numbers without space");
scanf("%d",&choise);

what is this?

you cant store an expression in an integer.

you need to store the expression as a string.
and then consider each character of the string, one at a time.

also are you supposed to only check if the brackets are balanced or if the expression is correct also?

example: (a +b + ) * ( a / ) here the brackets are balanced but expression is wrong.

if you have to check for brackets only , then push the character whenever you find ( and pop whenever you find ) ... you are doing that ...except you should handle the situation when you try to pop() when the stack is empty....(like in the example matsp gave)

but why break whenever you encounter a binary operator?

It's clear you don't have a clue what you're doing and this problem is too far above your difficulty level at this stage. All you've got are a bunch of random bits of code thrown together and you're just hoping that it in some way does something useful. Even then I'd guess that those bits were copied from someone else.
So there are two problems here:

1. You don't understand how to fully solve the problem
2. You aren't yet a proficient C Programmer

Which one of those would you like help with first?
How long have you got left for this assignment?

Originally Posted by angel_copra

what about this code....

Code:

for (int i=0;i<sizeof b;i++)
    {
    if (b[i]=='(')
        sum++;
    if (b[i]==')')
        sum--;
    if (sum<0)
        break;
    }

Ah now that code could actually do something useful. It doesn't solve the whole problem, but it does solve part of it, if you know what comes after it. However, unless you can demonstrate that you understand how that works, I'm inclined to believe that it is someone else's code.

Perhaps you could attempt to describe in your own words, the algorithm you will use to solve the problem. It doesn't matter if you get it wrong or get stuck, just give it a try and we'll give you a nudge.