READING FROM A FILE

> if ( count > 3)
It should be changed to "if ( count > 2)". You are starting from 0 and he wants anything more than 3!

And sanko50, sunnycoder has not given code for reading from a file. Hope you know that part already! Anyway, I will give steps to achieve this:
1. Open file "sample.txt".
2. read line to buffer "string". (sunny has hardcoded data of string. If you remove that and add my algorithm, then you will have complete code).
3. Repeat step# 2 till EOF.

Hope you can convert these to code and make it work!

thank you   sunnycoder  and   ssnkumar
    -----------------------------------

i have managed to implement the code usuing string only.
code
------
#include<stdio.h>

int main()

{
char last_char;
int count=0;
char string[] = "1 1 1 1 1 1 1 2 0 0";
char *temp = string;
last_char = *temp;

/* loop over input begin */

while(*temp != NULL)
{
while ( *temp == last_char )
{
     count++;
     temp = temp+2; //+2 for intervening space

}

if ( count > 2)
     /* print * last_char count*  */
     printf("*%c%d*",last_char,count);
else
     for(int i=0;i<count;i++)
     printf("%c",last_char);
      
last_char = *temp;
count = 0;

}
/* loop over input end*/
}

now i  am going to use FILE....as  ssnkumar pointed out i will pour the data first into buffer.
then  i have some question
--------------------------
question1 :  i have data around  int buffer[300000]. here  i usued  *temp != NULL for teminating the input loop.....but in case of buffer, how can i terminate????????

question2: i think i have to use temp=temp+4;  bcoz i have integer data , and in VC++ integer data takes 4 byte. am i right????

basically i will have my data stored in an integer buffer (not in a string)  so i have change a little bit??? is there any other change i have to do???

thanks

    temp = temp+2; //+2 for intervening space
take care that this does not put you beyond the end of  string

"take care that this does not put you beyond the end of  string "

hi ozo ... but  above code running correctly....why r u saying so?? temp=temp+2; ...i am increasing the addresses.....so at last i will reach to a addresses whose content is NULL and loop will  terminate.....

and  infact  this code is runing and giving me the result.....

it was usuing a string so NULL was the terminating character.....can you suggest how can terminate  the loop if it is an  int buffer[]?????

 

hi , i  have stored data in the buffer....and i want to  print like above
i am not getting successes , getting debug at the run time......simply i have changed char to integer... where is the mistake????

my code
-------------

#include<stdio.h>
int main()
{
   FILE *outfile = fopen("data.txt","w");
   int last_integer;
   int count =0;
   int buff[10]={1,1,1,1,1,1,-45,26,0,0};
   buff[11]='E';
   int* temp= buff;
   last_integer = *temp;
   
while(*temp != 'E')  // E is for termination

{
while ( *temp == last_integer )
{
     count++;
     temp = temp+4; // next integer

}

if ( count > 2)

{    
     printf("*%d%d*",last_integer,count);
     fprintf(outfile,"*%d%d*", last_integer,count); // writing in file also
}

     
else
      { for(int i=0;i<count;i++)
     printf("%d",last_integer);
     fprintf(outfile,"%d",last_integer);
      }
      
last_integer = *temp;
count = 0;
}

/* loop over input end*/
}
      
this code is giving runtime debug......

hi...i have done it.....i changed
int buff[20]={1,1,1,1,1,1,-45,26,0,0}; buff[10]=-999;//for sentinel value
while(*temp != -999) // for termination
temp = temp+1// next integer...

although i am getting on the screen correct result.....but in my file last 0 is not coming....
output in the screen
----------------------
*16*452600

output in the file
------------------
*16*45260 // last 0 is absent!!!!!!!!!!

had it not been 0 as the last character in the buffer,everything goes fine....what happened to the file...why it has absorbed the last zero???
N.B : i opened file in the notepad and notepad


************************************************************
i want also one algorithm for decoding also....i.e given  *16*452600  this in the file i will expand this into 1,1,1,1,1,1,-45,26,0,0  into a buffer.....that is just the opposite thing .....  plz  can you give SOME STEPS TO start with???????????

many many thanks.......

One small change to your code!
Put both printf() and fprintf() statements after the for loop inside braces.
Original code:
else
     { for(int i=0;i<count;i++)
     printf("%d",last_integer);
     fprintf(outfile,"%d",last_integer);
     }
After change:
     else
     {
        for(int i=0;i<count;i++)
        {
           printf("%d",last_integer);
           fprintf(outfile,"%d",last_integer);
        }
     }

One more suggestion: Follow indentation properly:-)

Steps for the decoding part:
1. Read from file to a character buffer.
2. Start scanning the buffer, char by char.
3. Repeat steps 4-8 for each scanned char.
4. If the current char is '*', then read the next char and store it in temp_char.
5. Read the next chars (and also keep count of these) till another '*' is found.
6. Convert them to integer count.
6. Display the temp_char count times.
8. If the test of step 3 fails, then display the current char.

Hope this will help....

-ssnkumar

thank you for the reply ..yes i have corrected the first part....and trying to do the second part(decoding)....in fact i  have  thought about your algorithm....

one confusion is there in your  step 6 :  " Convert them to integer count "  in fact i am thinking for that........


say i have something like below....

*135*1234  you will read first ' 1'  '3'  '5'  then you will repeat 1  (10*3+5)=35 times....probabily you wanted to mean this by your step 6.


other confusion  is, say , instead of printing  the  output i want to store in the  INTEGER  buffer( i want to store ,not to
print ) so in that case if i read according to char by char then  1234  of   *135*1234 will be stored as
  buff[i]=1  buff[i+1]=2 buff[i+2] =3 buff[i+3]=4

but may be in the encoder i wanted to mean 1234 = 12  34  ( two different number)

natuarally i would expect in the decoder buffer like  buff[i] =12  and buff[i+1]=34 (which is not possible if i read char by char)

so meaning will be completely changed !!!!!!

if at the storing time i could not distinguish these  difference then my data processing will be wrong.

in fact priniting will not cause any problem but storing will create problem ...so i have to be cautious at the storing time. how can i store properly ?????

that is why i am not able solve till now...........

waiting for your reply for any suggestion

thanks

1. Regarding confusion# 1:
>*135*1234  you will read first ' 1'  '3'  '5'  then you will repeat 1  (10*3+5)=35 times....probabily you wanted to mean this by your step 6.
What you have understood is correct and hope that's what your expectation is also.....!? If yes, Then there is no confusion:-))

2. Till now, I was thinking that, you have only single digit numbers!
    If you want to take care of digits with more than one digit, then a small addition/change to your algorithm.
    I will write the steps to be followed from step 8. (other steps remain the same)

8.   If the test of step 4 fails, THEN,
9.   BEGIN
10.     int temp_num = 0.
11.     read the next char into temp_char.
12.     while temp_char is not equal to space (' ') DO,
13.     BEGIN
14.         temp_num = (temp_num * 10) + (temp_char - '0').
15.         read the next char into temp_char.
16.     END (OF WHILE)
17. END (OF IF)

So, whatever is stored in temp_num after step 17 is your number.
Hope this works:-)

hi, i am sorry still i could not make it......after putting efforts still i am getting wrong results.....i have been debugging a lot to find it the logical error and to fix it....but not been successful yet....

based upon your STEPS i wrote

code
---------

#include<stdio.h>
#include<stdlib.h>
int main()
{
 FILE *infile;
   
 int k, i=0;
 static int p=0;
 int MY_BUFFER[100]; // to get output
 char buff[100];  // to store from file
 
 char var,temp_char,read_char;
 
 infile = fopen("c:\\abc.txt","r");
 if(infile == NULL) printf(" file can not be opened");
   
read_char='A';   // any character to start
 
fscanf(infile,"%c",&var);

while(!feof(infile))
 {
 
  buff[i]=var;
 
  i=i+1;
  fscanf(infile,"%c",&var);   //
 
 }
 buff[i]='\0';  // sentinel to stop the loop below
    k=0; int count = 0;


  while(buff[k]!='\0')  // scanning the buffer
 {
       
  if(buff[k]=='*')

  {  
     
        
        temp_char=buff[k+1];
         
      int  temp_num1=0;
      int m =k+2;
        
      read_char=buff[m];


      while(read_char!='*')
      {  
       count=count+1;
       temp_num1 = (temp_num1*10)+(read_char-'0');
       read_char=buff[m+count];  
     
         //  k = k+1;
     
      }
     
        k =m+count;

        k=k+1;

     

        
      for(int N=0;N<temp_num1;N++)
      {  
       
      MY_BUFFER[p]=(temp_char-'0');
        
      p++;
     
      }  
 
 
  }  // end of if
 
 
  int temp_num2=0;
  temp_char=buff[k];  
  int count2=0;
 
  while(temp_char !=' ')   // untill a gap
  { count2=count2+1;  
   temp_num2 = (temp_num2*10)+(temp_char - '0');
   temp_char = buff[k+count2];
  }
   
 
  k=k+count2;

  if(temp_num2 !=0)

  {
  MY_BUFFER[p] = temp_num2;
  p++;
  }
 
k=k+1;  

 }   // end while
 


 printf("\n\n\n");

for(int j =0;j<p;j++)

printf("%d\t",MY_BUFFER[j] );


}  // end of main


my sample input(in the file) :
-----------------------------------
123 *124* 5 6 7 8 9  //( note the spaces)

output i am getting in the MY_BUFFER[j]
-----------------------------------------------

123     1       1       1       1       1       1       1       1       1
1       1       1       1       1       1       1       1       1       1
1       1       1       1       1       5       6       7       8       12362332
84      Press any key to continue


as you see i am missing 9 in MY_BUFFER[] !!!!!!!!!  and also some other garbages has come also!!!!!!!!

where have i gone wrong????????? how can i fix it???????

THANKS FOR THE HELP

There is a small problem when you reach the last char!
The next char after the last char can be a '\0' or '\n'!! You have take care of this also. So change your while statement to:

      while ((temp_char != ' ') && (temp_char != '\0') && (temp_char != '\n'))  // untill a gap

With this change your code should work perfectly:-)

-ssnkumar      

ok thanks....after correcting as per your suggestion...... it is working for THAT SAMPLE INPUT ONLY.


but  if give

sample input (from file)
----------------------------
123 *124* 5 6 *12* 7 8 9

and

sample input (from file)
----------------------------
123 *124* 5 6 7 8 9 *12*  

i  am not getting output at all!!!!!!!!
but my encoder may produce these type of output as well !!!!!....my decoder should be  GENERAL  so that it could handle  all type of output(from encoder) is not it????

so why my decoder fails to decode for these  above two  particular output???




N.B : i have usued 'a'  as a sentinel for my buff[]...is it creating any trouble??

thanks  

THANK YOU FOR THE PROMPT,CLEAR,NICE,AND ELABORATED DESCRIPTION  

yes .....its working now for all sequences....

in fact i tested

with the file input
---------------------
123 *124* 5 6 *12* 7 8 9
---space--------
123 *124* 5 6 7 8 9 *12*  


and i have got the correct result  for this ALSO!!!.....its ok now....fine...

actually i am trying to  COMPRESS THE FILE SIZE  by searching the repeation of character and using  CODING.

i would have been more happier if  i could  REMOVE THE SPACES  in the encoder output.  and  still the decoder could  decode the code correctly...........bcoz in that case  some more bytes (i.e spaces) could have been compressed, and consequently i could get a more compressed file..........but  probabily  i feel it would be difficult for the decoder if it do not find the spaces , what is your opinion?????????

anyway, upto this is enough for me.......

thanks