Calculate The Average of The Positive Numbers 0 in C++

How to Calculate the Average of Positive Numbers

The average (or arithmetic mean) of a set of numbers is calculated by summing all the numbers and then dividing by the count of numbers. When calculating the average of positive numbers, we first filter out any non-positive numbers (zero or negative).

For example, if we have the numbers [0, 5, -2, 3, 8], the positive numbers are [5, 3, 8]. The sum is 5 + 3 + 8 = 16, and the count is 3, so the average is 16 / 3 ≈ 5.333.

Special Case: All Numbers Are Zero

When all numbers in the input set are zero, the set of positive numbers will be empty. In this case, the average is undefined because you cannot divide by zero. Your program should handle this case appropriately, either by returning a special value or displaying an appropriate message.

C++ Code Example

Here's a complete C++ program that calculates the average of positive numbers, including handling the special case where all numbers are zero:

#include <iostream>
#include <vector>
#include <numeric>

double calculateAverageOfPositiveNumbers(const std::vector<double>& numbers) {
    double sum = 0.0;
    int count = 0;

    for (double num : numbers) {
        if (num > 0) {
            sum += num;
            count++;
        }
    }

    if (count == 0) {
        // Handle the case where there are no positive numbers
        return -1.0; // Special value indicating no positive numbers
    }

    return sum / count;
}

int main() {
    std::vector<double> numbers = {0, 5, -2, 3, 8};
    double average = calculateAverageOfPositiveNumbers(numbers);

    if (average == -1.0) {
        std::cout << "No positive numbers found in the input." << std::endl;
    } else {
        std::cout << "The average of positive numbers is: " << average << std::endl;
    }

    return 0;
}

This code defines a function calculateAverageOfPositiveNumbers that takes a vector of numbers and returns the average of positive numbers. If there are no positive numbers, it returns -1.0 as a special value. The main function demonstrates how to use this function.

Special Cases and Edge Cases

When implementing this calculation, consider these special cases:

• All numbers are zero: The function should return a special value or display a message indicating no positive numbers were found.
• Empty input: The function should handle an empty input vector appropriately.
• Single positive number: The average should be the number itself.
• All numbers are negative: The function should return a special value or display a message indicating no positive numbers were found.

Your implementation should handle these cases gracefully to ensure robustness.