Thread: Finding the min and max of a file of integers

Can someone please give me a hint as to what is wrong with my code? I cannot find the correct min and max of a file of integers.

insert

Code:

#include<stdio.h>
main()
{
    int count = 0, sum = 0, num, min = 0, max = 0, avg;
    FILE *fin, *fout;
    
    fin = fopen("in.txt", "r");
    fout = fopen ( "out.txt", "w");
    
    while ( fscanf( fin, "%d", &num) != EOF){
    count = count + 1;
    sum = sum + num;
        if (num>=max)
             max=num;
        else if (num<min)
             min=num;    
    }
    avg = sum/count;
    fprintf(fout, "The number of integer values in the input file = %d\n", count);
    fprintf(fout, "The minimum integer value in the input file = %d\n", min);
    fprintf(fout, "The maximum integer value in the input file = %d\n", max);
    fprintf(fout, "The average of the integer values in the input file = %d\n", avg);    
    fclose(fin);
    fclose(fout);
}

Pretty sure your assignments are backwards.
max = num;
min = num;
Not vice versa.

Edit: So that advice didn't fix it? What do you see?

There is a chance that the real minimum and maximum is smaller or larger than 0. To protect yourself from that issue you can do a priming read and set both min and max to the first number:

Code:

    if (fscanf (fin, "%d", &max) == 1) { 
       min = max;
       rewind(fin);
    }
    while ( fscanf( fin, "%d", &num) != EOF){
    count = count + 1;
    sum = sum + num;
        if (num>=max)
             max=num;
        else if (num<min)
             min=num;    
    }

Originally Posted by whiteflags

He was assigning max and min to num in the original post,

so your first comment has nothing to do with what I see now in the first post. For what I see now my assumption is that num does not get any initialization values it should contain what ever is on the memory aka garbage. Am I correct?

Originally Posted by whiteflags

which he had time to edit and incorporate what I pointed out.

That is why I always quote what I'm answering to.

EDIT:
By the way loose the else in your comparison eg

Code:

     if (num>=max)

          max=num;

     if (num<min)

          min=num;

otherwise some number might never make it to the min comparison.

otherwise some number might never make it to the min comparison.

This is why I initialized the min and the max to the first number in the sequence. It becomes a strict weak ordering problem. If you look over the rules, you will see there is no number that can be less than the current min and greater than the current max at the same time. If there were some number, it would mean that you can't put the set in ascending order.

This is why selection sort actually works.