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Jul 9th, 2005

Error reading file

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i tried this

C++ Syntax (Toggle Plain Text)
#include <fstream>
#include <iostream>
#include <cstdlib>
using namespace std;
 
 
int main() 
{
    // Declare input stream
    ifstream fin;
    int min, max, val;
    int isFirst = true;
    fin.open("inFile.txt");
 
 
 
	fin >> isFirst;
    min = isFirst;
    max = isFirst;
 
    while (fin >> val)
    {
 
          fin >> val;
          if (val < min)
          val = min;
          else
          val = max;
 
    }
 
 
 
    fin.close();
 
    cout << "Largest value is " << max << ", smallest value is " << min << "\n";
	return 0;
}
#include <fstream>
#include <iostream>
#include <cstdlib>
using namespace std;


int main() 
{
    // Declare input stream
    ifstream fin;
    int min, max, val;
    int isFirst = true;
    fin.open("inFile.txt");



	fin >> isFirst;
    min = isFirst;
    max = isFirst;

    while (fin >> val)
    {

          fin >> val;
          if (val < min)
          val = min;
          else
          val = max;
		  
    }



    fin.close();

    cout << "Largest value is " << max << ", smallest value is " << min << "\n";
	return 0;
}

<< moderator edit: added code tags: [code][/code] >>
and it prints this
Largest value is 1, smallest value is 1
Press any key to continue
can someone suggest me what's i am doing wrong here

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desidude

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Jul 9th, 2005

Re: Error reading file

C++ Syntax (Toggle Plain Text)
    while (fin >> val)
    {
 
          fin >> val;
          if (val < min)
          val = min;
          else
          val = max;
 
    }
    while (fin >> val)
    {

          fin >> val;
          if (val < min)
          val = min;
          else
          val = max;
		  
    }

Change min and/or max, not val.

C++ Syntax (Toggle Plain Text)
   while ( fin >> val )
   {
      if ( val < min )
      {
         min = val;
      }
      if ( val > max )
      {
         max = val;
      }
   }
   while ( fin >> val )
   {
      if ( val < min )
      {
         min = val;
      }
      if ( val > max )
      {
         max = val;
      }
   }

It might also be helpful to post the contents of "inFile.txt".

Dave Sinkula

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Jul 9th, 2005

Re: Error reading file

i tried the way u suggested me but it still gives same output
the content of "inFile.txt" is
100
45
74
45
86
94
75
96
56
85
82
88
88
56
77

desidude

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Jul 9th, 2005

Re: Error reading file

>i tried the way u suggested me but it still gives same output
Odd.

C++ Syntax (Toggle Plain Text)
#include <fstream>
#include <iostream>
using namespace std;
 
 
int main() 
{
   ifstream fin("inFile.txt");
   int min, max, val;
   if ( fin >> val )
   {
      min = max = val;
      while ( fin >> val )
      {
         if ( val < min )
         {
            min = val;
         }
         if ( val > max )
         {
            max = val;
         }
      }
   }
   cout << "Largest value is " << max << ", smallest value is " << min << "\n";
   return 0;
}
 
/* my output
Largest value is 100, smallest value is 45
*/
#include <fstream>
#include <iostream>
using namespace std;


int main() 
{
   ifstream fin("inFile.txt");
   int min, max, val;
   if ( fin >> val )
   {
      min = max = val;
      while ( fin >> val )
      {
         if ( val < min )
         {
            min = val;
         }
         if ( val > max )
         {
            max = val;
         }
      }
   }
   cout << "Largest value is " << max << ", smallest value is " << min << "\n";
   return 0;
}

/* my output
Largest value is 100, smallest value is 45
*/

Dave Sinkula

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Jul 9th, 2005

Re: Error reading file

i tried every possible way u suggested me and it still doesnt work. could it be some other problem?

desidude

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Jul 9th, 2005

Re: Error reading file

Did you copy and paste what dave wrote and compiled it?

winbatch

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Jul 9th, 2005

Re: Error reading file

>fin >> isFirst;
I think you mean:

C++ Syntax (Toggle Plain Text)

fin>> val;

isFirst doesn't strike me as a data variable, it seems more like a status variable. You don't even need it. Oddly enough, I didn't bother looking at Dave's code, but my solution is only slightly different (but it avoids undefined behavior in the case of an empty or non-existent file):

C++ Syntax (Toggle Plain Text)
#include <fstream>
#include <iostream>
using namespace std;
 
int main() 
{
  ifstream fin("inFile.txt");
  int val;
 
  if (fin >> val) {
    int min, max;
 
    min = max = val;
 
    while (fin >> val)
    {
      if (val < min)
        min = val;
 
      if (val > max)
        max = val;
    }
 
    cout << "Largest value is " << max << ", smallest value is " << min << "\n";
  }
 
  return 0;
}
#include <fstream>
#include <iostream>
using namespace std;

int main() 
{
  ifstream fin("inFile.txt");
  int val;

  if (fin >> val) {
    int min, max;

    min = max = val;

    while (fin >> val)
    {
      if (val < min)
        min = val;

      if (val > max)
        max = val;
    }

    cout << "Largest value is " << max << ", smallest value is " << min << "\n";
  }

  return 0;
}

Great minds think alike, I suppose.

>i tried every possible way u suggested me and it still doesnt work.
Then instead of looking at the suggestions and implementing them they way you think they should be done, actually try them as they are written. In my experience, Dave doesn't post untested code.

Narue

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Jul 9th, 2005

Re: Error reading file

thx a bunch guys
i am sorry dave it was my fault in implementing codes . its working
thx

desidude

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Jul 9th, 2005

Re: Error reading file

again need help guys
trying to calculate average of all numbers in previous program
here is what i did but it gives average = 77

C++ Syntax (Toggle Plain Text)
#include <fstream>
#include <iostream>
#include <cstdlib>
using namespace std;
 
 
 
int main() 
 
{
 
   ifstream fin("inFile.txt");
   ofstream fout("outFile.txt");
 
   if (fin.fail())
   {
	   cout<<"Input file opening failed.\n";
	   exit(1);
   }
   if (fout.fail())
   {
	   cout<<"output file opening failed.\n";
	   exit(1);
   }
   int min, max, val;
   double sum = 0;
   int count = 0, next ;
 
 
 
   if ( fin >> val )
 
   {
 
 
      min = max = val;
      while ( fin >> val )
      {
 
 
         if ( val < min )
         {
            min = val;
         }
 
         if ( val > max )
         {
            max = val;
		 }
 
      }
	  sum = sum+val;
	   count=count++;
 
   }
 
 
 
 sum=sum/count;
 
 
 
   fout<<"average score is:"<< sum << "\n";
   cout<<"average score is:"<< sum << "\n";
 
 
   fout << "Largest value is " << max << ", smallest value is " << min << "\n";
   cout << "Largest value is " << max << ", smallest value is " << min << "\n";
   fin.close();
   fout.close();
 
   return 0;
}
#include <fstream>
#include <iostream>
#include <cstdlib>
using namespace std;



int main() 

{
   	
   ifstream fin("inFile.txt");
   ofstream fout("outFile.txt");
   
   if (fin.fail())
   {
	   cout<<"Input file opening failed.\n";
	   exit(1);
   }
   if (fout.fail())
   {
	   cout<<"output file opening failed.\n";
	   exit(1);
   }
   int min, max, val;
   double sum = 0;
   int count = 0, next ;
          
 
	  
   if ( fin >> val )
	   
   {
	     
	  
      min = max = val;
      while ( fin >> val )
      {
		 
			  
         if ( val < min )
         {
            min = val;
         }
		 
         if ( val > max )
         {
            max = val;
		 }
		  
      }
	  sum = sum+val;
	   count=count++;

   }
           
   

 sum=sum/count;
	

   
   fout<<"average score is:"<< sum << "\n";
   cout<<"average score is:"<< sum << "\n";

   
   fout << "Largest value is " << max << ", smallest value is " << min << "\n";
   cout << "Largest value is " << max << ", smallest value is " << min << "\n";
   fin.close();
   fout.close();
   
   return 0;
}

Code tags added. -Narue

what am i doing wrong here?

desidude

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Jul 9th, 2005

Re: Error reading file

>here is what i did but it gives average = 77
Um...what's the problem with getting the correct answer?

Narue

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