Complementary task for topic: 2

#include 

int main() {
    int number;
    int sum = 0;
    int count = 0;
    
    printf("Enter a number (-1 to stop): ");
    scanf("%d", &number);
    
    while (number >= 0) {
        sum += number;
        count++;
        
        printf("Enter a number (-1 to stop): ");
        scanf("%d", &number);
    }
    
    if (count == 0) {
        printf("No numbers entered.\n");
    } else {
        double average = (double)sum / count;
        printf("The average of the numbers entered is %.2f.\n", average);
    }
    
    return 0;
}

In this example, the program initializes the number variable to store the user input, the sum variable to keep track of the sum, and the count variable to keep track of the number of inputs. It uses printf() to prompt the user to enter a number and scanf() to scan the input and store it in the number variable. The program then enters a while loop that continues as long as the number entered by the user is greater than or equal to 0. Inside the loop, it adds the current number to the sum and increments the count. After each iteration, it prompts the user to enter another number using printf() and scanf() to repeat the process. Once the user enters a negative number, the loop terminates. If no numbers were entered (i.e., count is 0), it displays a message stating that no numbers were entered. Otherwise, it calculates the average by dividing the sum by the count (casting sum to a double to ensure floating-point division) and uses printf() to display the average.