How to write a program that calculates the average of the inputted positive numbers and ignores the negatives

Question

Following are the problem, my code and my question:

Do not use an array to hold numbers that user enters in this exercise! Write a program that calculates average of positive numbers that user enters. Program asks user to enter numbers and calculates the average of entered numbers when user enters 0 as the number. The zero is not included in the average. If user enters a negative number the program must print a message telling that only positive numbers are accepted and ignore the negative number.

Here's most of the code written:

#pragma warning (disable:4996)

#include <stdio.h>

int main() {
    int number;
    int sum = 0;

    printf("Please enter the 1st number or 0 to stop: ");
    scanf("%d", &number);

    int count = 0;

    while (number != 0)
    {
        sum = sum + number;
        count++;
        printf("Please enter another number or 0 to stop: ");
        scanf("%d", &number);
    }
        
    if  (count < 0) {
        printf("Only positive numbers\n");
    }
                    
    if (count > 0)
    {
        printf("AVERAGE = %f", ((float)sum) / count);
    }

} 

SPECIFIC QUESTION: If a user enters a negative number, how can I not let it affect the average and prompt the user to enter a positive number?

Answer 1

The following code is working as desired :-

#include <stdio.h>

int main()
{
    int number;
    int sum = 0;
    int count = 0;         

    printf("Please enter the numbers and enter 0 to stop ");
    scanf("%d", &number);

    while (number != 0)
    {
        if (number > 0) {
            sum += number;
            count++;      // increase the count only when a positive number is entered
        }
        else {
            printf("Enter only positive numbers\n");
        }

        printf("Please enter another number or 0 to stop: ");
        scanf("%d", &number);
    }
    printf("AVERAGE = %f", ((float)sum) / count);
}

The problem with Rasumus' code is that it's increasing the count even when a negative number is entered, that will show erroneous average value.

Answer 2

#include <stdio.h>

int main() {
  
  int number;
  int sum = 0;
  int count = 0;

  printf("Please enter the 1st number or 0 to stop: ");
  scanf("%d", & number);


  while (number != 0) 
  {
     if (number > 0) 
     {
         sum = sum + number;
         count++;
     }
     else 
     {
         printf("only positive numbers are accepted\n");
     }

   printf("Please enter another number or 0 to stop: ");
   scanf("%d", & number);
   }

  if (count > 0) 
  {
    printf("AVERAGE = %f", ((float) sum) / count);
  }
  if ( count == 0)
  {
      printf(" no numbers to calculate average.");
  }
  return 0;
} 

Answer 3

#include <stdio.h>

int main() {
  int number;
  int sum = 0;

  printf("Please enter the 1st number or 0 to stop: ");
  scanf("%d", & number);

  int count = 0;

  while (number != 0) {
    if (number > 0) {
      sum = sum + number;
      count++;
    } else {
      printf("only positive numbers are accepted\n");
    }

    printf("Please enter another number or 0 to stop: ");
    scanf("%d", & number);
  }

  if (count > 0) {
    printf("AVERAGE = %f", ((float) sum) / count);
  }
  return 0;
} 

Answer 4

You checked if the amount of times the user entered something is negative (which it can never be). Instead just make an if statement before u add the number to the sum.

#include <stdio.h>

int main() {
    int number;
    int sum = 0;

    printf("Please enter the 1st number or 0 to stop: ");
    scanf("%d", &number);

    int count = 0;

    while (number != 0)
    {
        if (number > 0) {
            sum = sum + number;
        } else {
            printf("Only positive numbers\n");
        }
        
        count++;
        printf("Please enter another number or 0 to stop: ");
        scanf("%d", &number);
    }
                         
    if (count > 0)
    {
        printf("AVERAGE = %f", ((float)sum) / count);
    }

}