Thread: Help with C Program

Hello Everyone,

I'm tying to make a C program which determines the level of bacteria for some beaches.
The program is supposed to access the data from a txt file and give the result.

Here's what I've been able to do so far.
I have no idea where to go from here, so please help!!

The text file is attached. The first number in the txt file refers to the lake ID, the second number to the beach number, the third number refers to the number of samplings and the rest of the numbers are the samplings of the number of organisms in 100ml of water.

Code:

#include <stdio.h>

int
main (void)
{ 
	FILE * july01;
	
	int lake_id, beach_num, num_samplings, num;
	double num_organisms, tot_organisms;
		
	july01 = fopen ("july01.txt", "r"); 
	
	tot_organisms = 0;	
		
	while (fscanf (july01, "&#37;d %d %d", &lake_id, &beach_num, &num_samplings) != EOF) 

  {
	 tot_organisms = 0; 
	
	for (num = 1; num <= num_samplings; num++)
	  	{			
		fscanf(july01, "%d",  &num_organisms);		
		tot_organisms = tot_organisms + num_organisms;
		}

	if  (((tot_organisms / num_samplings) / 100) > 0.5)
		printf ("Close");

	else if  (num_samplings < 3)
		printf ("Insufficient Data");

	else if  (((tot_organisms / num_samplings) / 100) <= 0.5)
		printf ("Open");
			
  }
  
 fclose (july01);
}

Here are the conditions for the program

If the average level is above 50/100ml, close the beach.
If there are less than 3 samplings, there is insufficient data.

The program should show for each beach on separate lines the name
of the lake, the name of the beach, and the recommendation ("open",
closed" or "insufficient data"). Use the table below to convert IDs
and numbers into names.

Lakes
1: Ontario
2: Erie
3: Huron

Beaches
101: Kew Beach
102: Sunnyside Beach
201: Port Dover
202: Port Burwell
301: Goderich
302: Sauble Beach

> for (num = 1; num <= num_samplings; num++)
> fscanf(july01, "&#37;d", &num_organisms);
> tot_organisms = tot_organisms + num_organisms;
Add more curly braces to your code to indicate what you really mean.
Despite your indentation, the red code is NOT in the loop


> fscanf(july01, "%d", &num_organisms);
The format and the data type don't match.

Also, it's not a good idea to mix spaces and TABS when writing code, especially if you intend to post that code on a forum, in an email, in another editor.

&#37;d is for an int, you've suppied a double.

Should be "&#37;lf", not "%if" (in case that wasn't a typo). Better yet, make num_organisms an int, and only use double for those variables that actually need to be floating point (you can use a cast to force floating-point division where necessary).

Originally Posted by ssharish2005

Code:

((tot_organisms / num_samplings) / 100)

This will provide you with the normal integer value. It would be better if you change the 100 to 100.0 or you will have to tpye cast.

ssharish

If either tot_organisms or num_samplings is a floating-point type, the whole calculation will be done that way. If not, then tot_organisms/num_samplings will be computed as an integer, and truncated accordingly, and making 100 into a double by using 100. won't fix that. If both tot_organisms and num_samplings are integer types, then one of them needs to be cast to a floating-point type to make the division work as intended. Alternatively, the whole expression could be modified to make it work with integers. For example,

Code:

((tot_organisms / num_samplings) / 100) > 0.5

could be replaced by

Code:

tot_organisms > 50*num_samplings

Without seeing your latest code, not a chance.

asdas

Code:

$ gcc -W -Wall -ansi -pedantic -O2 new.c
new.c: In function `main':
new.c:23: warning: float format, double arg (arg 3)
new.c:83: warning: control reaches end of non-void function

The first one relates to
fscanf(july01, "&#37;f", &num_organisms);
Use "%lf" to scan into a double.