programming logic || scared

centr0 · 07-07-2003, 09:28 PM

im just learning to program in C. when i read the book that i have i can understand the code and what it does. but if you ask me to create a program similar to the one in the book i wouldnt know where to start.

i guess my question is. is there any sites for programming logic in C? or does this stuff just flow right in once i get comfortable with the language? its kind of scary. =\

Tinkster · 07-07-2003, 09:40 PM

Just keep doing it :)

It's like getting familiar with a foreign
language ;) ... you'll get the hang of it.

Cheers,
Tink

centr0 · 07-08-2003, 01:16 PM

im trying to follow an exercise in a book i have. it asks to copy input to output and replace each string of one or more blanks with a single blank. now i know i need to test for blank spaces. but how would i go about testing for more blank spaces? im not asking for the answer. just a kick in the right direction. =)

kev82 · 07-08-2003, 01:35 PM

i would think about it like this, you want to copy every charcter thats not a space preceeded by a space. hope that helps.

TheLinuxDuck · 07-08-2003, 01:35 PM

So, it's looking for a string that may or may not contain blank spaces as well as other text, or will the strings contain only blank spaces?

coolman0stress · 07-08-2003, 06:00 PM

Practice, practice and more practice!

centr0 · 07-09-2003, 12:01 AM

Quote:

Originally posted by TheLinuxDuck
So, it's looking for a string that may or may not contain blank spaces as well as other text, or will the strings contain only blank spaces?

it will contain characters and spaces. im trying to replace the one or more spaces with a single space only without neglecting the characters that come after the multiple space.

Quote:

Originally posted by kev82
i would think about it like this, you want to copy every charcter thats not a space preceeded by a space. hope that helps.

i wrote something that neglects the spaces completely but i dont know how to putchar() something right after a space?

shellcode · 07-09-2003, 01:26 AM

hint:
a loop
stores the character that getchar() got before in a variable
then compare the variable
ie.
if the last char whas a space then print nothing....

what book?
this sounds like an execrise from K&R...

centr0 · 07-09-2003, 04:17 AM

Quote:

Originally posted by shellcode
what book?
this sounds like an execrise from K&R...

it is k&r exercise1-9. =)

i declared 2 ints c,d and started loop:

while((c = d = getchar()) != EOF)

and tried various if statement to compare but i always get errors when i try to compile.
[edit] and by reading the book. it hasnt even covered if statements so it must be possible to accomplish this exercise without if statements right?[/edit]

i know i need to compare c and d for spaces and if c is a space and d is a space, then neglect d. but then dont i need to test if the next c is a space and neglect that? am i on the right track or am i way off?

given the while statement i entered here wont my string look like this regarding variables.

cdcdcdcdcdc ...etc?

man i hope i get the hang of this logic stuff. its the first chapter and it takes this long to complete one exercise lol. thanks in advance for your help.

shellcode · 07-09-2003, 03:47 PM

the first chapter is the fastest (if you know no C) since it tries to introduce you to C quickly.

The K&R book is the best but its not really meant for beginners that much......

you only need:

while ((c = getchar()) != EOF)

but youll want another variable to take care of the first getchar()

this is also a good site for C questions:
www.cprogramming.com

have fun! once you learn it you wont regret you spent your time..

centr0 · 07-09-2003, 09:06 PM

Code:

main()
{
   int c,d;

   while((c = getchar()) != EOF)
   {
       d = getchar();
       if(d == ' ')
               putchar(c);
       else{
               putchar(c);
               putchar(d);
       }
    }
}

with the help of all who have responded i figured how to get 2 spaces and replace it with one. i have pasted the code here to see what you guys think.

is there a better way to do this?

how can i replace more than 2 spaces with a single space? or is this asking too much since im a beginner? =)

shellcode · 07-09-2003, 09:39 PM

Quote:

Originally posted by centr0

is there a better way to do this?

yes there is...consider a loop which places the result of getchar() in a variable as the last thing it does

Quote:

this asking too much since im a beginner? =)

nah, keep trying.....

have fun!

kev82 · 07-10-2003, 04:22 AM

how about storing the current character from getchar() in one variable and having another variable that stores the character from the previous iteration then use the values of these characters to determine if you should display the current one.