Error reading file

[desidude]

i tried this

#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;
}

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

[Dave Sinkula]

while (fin >> val)
    {

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

Change min and/or max, not 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".

[desidude]

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

[Dave Sinkula]

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

#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
*/

[desidude]

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

[winbatch]

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

[Narue]

>fin >> isFirst;
I think you mean:

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):

#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.

[desidude]

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

[desidude]

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

#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?

[Narue]

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

[Rashakil Fol]

The average is 76.4666.

desidude, since your sum and count are modified after the while loop, only the last value of your numbers gets added to sum, and count gets incremented once, from zero to one. And 77 is your last value.

[zyruz]

Just put the

sum = sum+val;
   count=count++;

inside your while loop, and it shuld work.

[desidude]

Zyruz, i tried that before but it gives 74.78 which is 1047( 100 less than total(1147))/14(it is suppose to be 15).

[Narue]

Don't forget to account for the first value:

if ( fin >> val )
  {
    sum += val;
    ++count;
    min = max = val;

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

      if ( val > max )
      {
        max = val;
      }

      sum += val;
      ++count;
    }
  }

On a side note, this is very, very wrong:

count=count++;

It modifies count twice between sequence points, which is undefined.

[desidude]

thx alot guys