Function to delete space and to add space again...

Contributor
3Dec2008,21:34   #1
back from retirement's Avatar
I was trying to generate a function that will delete all the spaces from a given passage. I was successful....my program may look a bit clumsy....but it is working on pretty fine....

Code: C
#include<stdio.h>
#include<conio.h>
#include<string.h>
#include<malloc.h>

char *spacedel(char *a)
{
    char *b;
    int i, j, c=0, l=strlen(a);
    for(i=0;i<l;i++)
    {
        if(*(a+i)==' ')
            c++;
    }
    b=(char *)malloc((l-c)*sizeof(char));
    i=0;
    j=0;
    while(i<l && j<(l-c))
    {
        if(*(a+i)==' ')
            i++;
        else
        {
            *(b+j)=*(a+i);
            i++;
            j++;
        }
    }
    return(b);
}

void main()
{
    char a[]="C is the philosophy of life.";
    char *b;
    b=spacedel(a);
    printf("\n%s", b);
    getch();
}

Immediately after this I was given an assignment to retreat the sentence, I mean say the sentence initially given was...

Code:
C is the philosophy of life.
After running through my program it becomes...
Code:
Cisthephilosophyoflife.
Now, I have to retain it to its original form.....with the use of another function....

How on the earth am I gonna do that???????
Please help....I am getting confused even in tracing out my process....
Go4Expert Founder
3Dec2008,21:42   #2
shabbir's Avatar
Not possible unless you have a dictionary. Everything is not irreversible.
Mentor
3Dec2008,22:22   #3
xpi0t0s's Avatar
Will the call to the new function always be preceded by a call to the existing function?
If so then you can reverse the process by storing a list of locations where you removed spaces from.

Otherwise Shabbir's correct; if you're just writing a new program to get "C is the..." out of "Cisthephilosophyoflife." then you need to know somehow that C, is, the etc are words that would normally be followed by spaces, and this is further complicated by the fact that "I" is a word, so you could end up well confused if you start decoding the string as "C I ". So you will need some way of determining how long a word is. Also you'd need to make sure that "life" isn't followed by a space.
Contributor
5Dec2008,10:25   #4
back from retirement's Avatar
Yes....the new function call will be preceded by the spacedel one....

Please tell me how to proceed then....
Go4Expert Founder
5Dec2008,10:28   #5
shabbir's Avatar
Quote:
Originally Posted by back from retirement View Post
Yes....the new function call will be preceded by the spacedel one....

Please tell me how to proceed then....
Store the position of the spaces in some array and introduce them back.

The other way is store the initial one and then return when called by second function
Contributor
5Dec2008,10:31   #6
back from retirement's Avatar
Excuse me.....how will I store spaces in an array????

like this??

Code: C
for(i=0;i<5;i++)
a[i]=" ";
Mentor
5Dec2008,13:16   #7
xpi0t0s's Avatar
How will that help restore the original array?
Can you think of something else you might store instead of the spaces themselves?
Actually I already gave you one possibility in my previous post but you missed it.
Go4Expert Founder
5Dec2008,13:23   #8
shabbir's Avatar
No just the index.

Say an Array of your string is

arrStrSrc[] = "This is the Array"
arrStrDest[] = "ThisistheArray"
arrSpaceLoc[] = {4,7,11}

Remember to be consistent in storing the location of Src or Destination.
Contributor
5Dec2008,13:43   #9
back from retirement's Avatar
Yeah....and that can be done while I'm sliding the pointer along the given string at the first time...
I can introduce a counter....
Whenever the pointer experiences a space, the current value of the counter will be stored in another array....that will give the locations of the space....

That fixes it much....I hope....

One more query, what if I have to write a program which contains multiple spaces....and I have to reduce them in single space....

e.g. Consider the following sentence...
Code:
C  is the    philosophy  of     life.
And I have to write it as....
Code:
C is the philosophy of life.
What program should I write?? Please give hint....

Of course, I have to write a function....and pass that sentence in it to get that output....

Last edited by back from retirement; 5Dec2008 at 13:47..
Go4Expert Founder
5Dec2008,14:21   #10
shabbir's Avatar
Replace all double space into single space and loop till you can find double space at least once.