Can someone help me please, I have to other documents as inputs and outputs

[james121285]

I have written a program that will take the max and min of 10 set values. I have to now change my program to allow for these inputs to be entered in by another document, and print the values into another document.

#include<stdio.h>
int
main ()
{
  int i;
  int a[10] = { 10, -99, 888, 4, 234, 1, 30, 40, 22, 34 };
  int max = a[0];
  int min = a[0];
 
 
  for (i = 0; i < 10; i++)
    {
      if (a[i] > max)
        {
          max = a[i];
        }
      else if (a[i] < min)
        {
          min = a[i];
        }
    }
  printf ("Maximum  : %d\n", max);
  printf ("Minimum  : %d\n", min);
 
  return 0;
}
 
/* This is the section I have been trying to add but I dont no where, can someone help me please. */
 
 FILE* fp;
  fp = fopen("mydata.txt", "r");
 
  FILE* fp;
  fp = fopen("output.dat", "w");

[Ganon11]

First, you'll need to name the file pointers something different from each other, rather than fp.

You should put these statements in the beginning of your program. Then, when reading into your array, instead of assigning values to it using the { 1, 2, 3 } notation, read them into the array using a for... loop.

Finally, instead of using printf() to output to the console, use your output file pointer to output to the file - I think it's fprintf()?

[james121285]

I have made a few changes but I dont really understand it. Can anyone tell me were am going wrong this time or point me in the right direction. I have created both these documents but they are coming up as dat files, once I open the input file I cannot type values in, how is this.

Thanks for your time

#include<stdio.h>
int main ()
{
   FILE  *fi;
   FILE  *fo;
 
   fi = fopen("infile.dat","r");
   fo = fopen("outfile.dat","w");
   {
      FILE *fi; /* input file pointer */
      if ( (fi=fopen("infile.dat","r")) == NULL ) {
         printf("ERROR opening file!\n");
         return 1;  /* terminates program in error */
      }
      int i;
      int a[10] = { fi };
      int max = a[0];
      int min = a[0];
      for (i = 0; i < 10; i++)
      {
         if (a[i] > max)
         {
            max = a[i];
         }
         else if (a[i] < min)
         {
            min = a[i];
         }
      }
      fprintf (fo,"Maximum  : %d\n", max);
      fprintf (fo,"Minimum  : %d\n", min);
      fclose(fo);
      fclose(fi);
      return 0;
   }
}

[Ganon11]

I've added a couple comments to the code where I see some errors:

#include<stdio.h>
int main ()
{
   FILE  *fi;
   FILE  *fo;
 
   fi = fopen("infile.dat","r");
   fo = fopen("outfile.dat","w");
   {
      FILE *fi; /* input file pointer */
      if ( (fi=fopen("infile.dat","r")) == NULL ) { // You reopen fi here - it is opened in line 7!
         printf("ERROR opening file!\n");
         return 1;  /* terminates program in error */
      }
      int i;
      int a[10] = { fi }; // This is not a correct assignment statement.
      int max = a[0];
      int min = a[0];
      for (i = 0; i < 10; i++) // You can loop starting from 1 - you've already checked a[0]
      {
         if (a[i] > max)
         {
            max = a[i];
         }
         else if (a[i] < min)
         {
            min = a[i];
         }
      }
      fprintf (fo,"Maximum  : %d\n", max);
      fprintf (fo,"Minimum  : %d\n", min);
      fclose(fo);
      fclose(fi);
      return 0;
   }
}

In order to get the integer values from infile.dat, you will have to use fscanf with fi. Using the {} notation won't work, because you are trying to set an integer array to hold a file pointer - incompatible types.