Why doesn't the program work as it should be?

Question

0.00/5 (No votes)

See more:

Hello, i have to make this program, but i still haven't finished it and i need some help. This is what i have to do. Make a program in Pascal that after has read a text with a list of nums., it will return the numb. of the nums that appear less than one times in the text.

The text that will be read from the program should be like that.

In the first line there are two nums. seperated by a space, n and m. N is the number of nums that exist, like if the text contains the numbers 1,2,3,4, n is 4 (1..n). M is how many lines follow. Every line has a couple of nums, a,b, (1=b) a and b are separated by a space.

The file that the program will make will have written on it a num., that says how many nyms are appeared less than two tims in the text.

All the nums. are Integer.

0=

i've made the following program, but it only reads the first line of the text. Anyone that can help me? The deadline is almost ended. Thanks in advance. My code is the following.

I've made the code after that, the program is how to put into variables all the nums. I'm a beginner so if anyone could give me an example, would help a lot.
Example of the text that reds.
domes.in
6 7
2 4
4 1
3 5
4 3
1 3

Pascal

Program thefinalp;
  Uses SysUtils;
        
  Var
    f:Text;
    m,d:Integer;
    n:Char;
    c:String[1];
        
    a,e:array of integer;
    LowArr:Integer;
    HighArr:Integer;
    ArrayLen:Integer;
    i:Integer;
        
        
    begin
      Assign(f,'finalp.txt');
      Reset(f);
        
      repeat
        Read (f,n);
        Write(n);
      until (n=' ');
        
      Read(f,c);
      Write(c);
        
      readln(f,d);
      Writeln(d);
        
      StrToIntDef(n,m);
        
      setlength(a,m);
      LowArr:=Low(a);
      HighArr:=High(a);
      ArrayLen:=Length(a);
        
      setlen;
      LowArr:=Low(e);
      HighArr:=High(e);
      ArrayLen:=Length(e);
        
      for i:= LowArr to HighArr do
      begin
        repeat
          Read (f,a[i]);
          Write(a[i]);
        until (n=' ');
            
        Read(f,c);
        Write(c);

        readln(f,e[i]);
        Writeln(e[i]);
        
      End;

      Readln;
    End.

[edit]Code indentation added - OriginalGriff[/edit]
[edit]Fixed pre tag - Matt T Heffron[/edit]

Posted 25-Jan-14 22:35pm

Member 10538783

Updated 28-Jan-14 4:55am

v16

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2014-01-25T22:41:00

Solution 1

Because seekEoln[^] returns true if it is at the end of a line. Which it won't be the first time you enter the loop in your sth procedure, but will be immediately after calling readln...

And please, do yourself a favor: learn to indent your code so it is at least partly readable? It'll make your life a lot easier in the future, as well as our now... :sigh:

Posted 25-Jan-14 22:41pm

OriginalGriff

Comments

Member 10538783 26-Jan-14 4:57am

Thank you for the comments.I tried to indent my code a little beat, i hope it's better now. Em, about the seekEoln, do you mean that i shouldn't put readln but read? Although i'm not sure that this is what you meant.

OriginalGriff 26-Jan-14 5:24am

I've manually indented the code for you - and if you look closely the indentation reveals a bug: look at the "if eof..." line near the bottom - can you see a problem?
Easier to follow what is going on like that? :)

You are using seekEOLn as part of your loop check - so as soon as you are at the end of a line, the loop will exit. Perhaps you don't need it at all? Just the eof test?

Member 10538783 27-Jan-14 11:59am

Thanks for indenting my code, it's really clearer now what's is written. Now, about the eoln, i tried not to use it, but the last characters of the line are put together with other nums., into the same variable. The problem is that it must be in one variable isolated. Is there sth i could do?

OriginalGriff 27-Jan-14 12:26pm

Are you sure?
http://www.freepascal.org/docs-html/rtl/system/readln.html
Note:
"The end-of-line marker is not considered part of the line and is ignored."
Could it be that the Writeln is making it look like it is?

Member 10538783 27-Jan-14 12:43pm

Yes you're right the seekeoln shouldn't be the problem, i erased it and i corrected to the code there is under my question, but it still doesnt't work, is it possibly because of StrToIntDef(n,m)?

Member 10538783 27-Jan-14 12:57pm

I indented my code mannualy, because the indent buttn does not do anything.

OriginalGriff 27-Jan-14 14:09pm

I can't help you there - I have no idea what IDE/Compiler you are using!

OriginalGriff 27-Jan-14 14:11pm

When you say "doesn't work" what do you mean?
There are so many ways that something could "Not work" and only a couple in which it could! :laugh:
So explain what you expect, and what you get - exactly what you get - and how you know you have got it. ;)

Member 10538783 27-Jan-14 15:03pm

Yes, you're right, i'm sorry, the compiler i'm using is the Free Pascal Compiler, and i improved my question by puting more details, and by explaining what the program should do.

OriginalGriff 28-Jan-14 4:19am

OK - you seem to be doing things a bit randomly here... :laugh:
Almost as if you were using the famous design method of "hope and pray" ;)

Look at this code for example:
repeat
Read (f,n);
Write(n);
until (n=' ');

Read(f,c);
Write(c);

readln(f,d);
Writeln(d);

StrToIntDef(n,m);
What value is in "n" when you call StrToIntDef?
Answer: space. Always. Because your loop only ever ends when there is!
But that is pretty much irrelevant, because you don't use the value the function returns anyway...

Stop making changes at random.
Sit down for a moment, and think about this logically:
you have a task:
1) Read data from file.
1.1) First line is a spacial: it says how many lines there are (and probably, how many columns in each line)
1.2) The other rows contain columns of data.

So organise your application the same way:
Read a line
Convert it to numbers.
Use those to control the other lines

So what I would do is write a function which read a string line from the file, and returned an array of numbers from that. (If you don't know how to return an array, then have the function fill a global array, and return the number of data items it filled it with.)
I'd then call it once to process the first line, and use the return data to control the rest of the program.

So try that: ignore the rest of the file for a moment, and get it to reliably read the first line, process it into numbers, and then print the number of lines (and columns, if that's what it is). When that works, you can use the same code (that you know works!) to process the rest of the file.

Have a go: if you get stuck, I won't be too far away!

Member 10538783 28-Jan-14 11:01am

Hi, thank you verymuch for you're help and the time you spent helping me. I corrected my question, and added the hole program i have to make. I've made all the other program, so that's why i put only this part. When you say read a string line from the file, and returned an array of numbers from that, could you explain a little bit simpler what do you mean? I know that i should have known, but i'm a begginer, and i would search on the internet, but the dadline dues really soon, and i'm finishing the other parts.
Thank you very much.

OriginalGriff 28-Jan-14 11:23am

Well, you know how to read a line from a file - I know that! :laugh:
And, you know what an array is - you use them in your example.
So, if you declare a global array of integers to transfer data from your function to your main code, you could fill it in the function.

Inside the function, you read a line of text from your file.
Each line consists of a number of values, separated by spaces.
So convert each value to an integer and put it in the array.
(This may help - it does it with comma separated values, and doesn't do the conversion itself, but you know how to do that anyway!)
http://computer-programming-forum.com/29-pascal/de2df4ef0ac69c4a.htm
Look at 4/7: it breaks up the string and passes it to a function called DoWhatEver - you'd need to do the StrToIntDef there.

Member 10538783 28-Jan-14 14:26pm

Thank you very much, it was exactly what i was looking for.

OriginalGriff 28-Jan-14 14:27pm

You're welcome!

Richard MacCutchan 26-Jan-14 7:27am

Read (f,a
Reminds me of Mickey Flanagan. :)

OriginalGriff 26-Jan-14 8:04am

Sweet! F, A indeed!

(Fanny Adams gets around, doesn't she?)