Example: Series Sum Calculator with Constructor Overloading in C++

// Series Sum Calculator with Constructor Overloading
#include <iostream>

class SeriesSumCalculator {
private:
    int start_val;
    int end_val;
    int step_val;
    long long total_sum;

    // Private helper method to perform the actual sum calculation
    void performCalculation() {
        total_sum = 0;
        if (start_val > end_val) {
            // Handle cases where start > end gracefully
            return;
        }
        if (step_val <= 0) { // Safety check, though constructors ensure this
            step_val = 1;
        }

        for (int i = start_val; i <= end_val; i += step_val) {
            total_sum += i;
        }
    }

public:
    // Constructor 1: For sum from 1 to 'limit' (default step 1)
    SeriesSumCalculator(int limit) : start_val(1), end_val(limit), step_val(1) {
        if (limit < 1) { // Handle invalid limits
            std::cout << "Warning: Limit should be positive. Setting limit to 1." << std::endl;
            end_val = 1;
        }
        performCalculation();
    }

    // Constructor 2: For sum from 'start' to 'end' (default step 1)
    SeriesSumCalculator(int start, int end) : start_val(start), end_val(end), step_val(1) {
        performCalculation();
    }

    // Constructor 3: For sum from 'start' to 'end' with 'step'
    SeriesSumCalculator(int start, int end, int step) : start_val(start), end_val(end), step_val(step) {
        if (step <= 0) {
            std::cout << "Warning: Step value must be positive. Setting step to 1." << std::endl;
            this->step_val = 1;
        }
        performCalculation();
    }

    // Method to get the calculated sum
    long long getSum() const {
        return total_sum;
    }

    // Method to display series parameters
    void displaySeriesParams() const {
        std::cout << "Series: Start=" << start_val << ", End=" << end_val
                  << ", Step=" << step_val << ", Sum=" << total_sum << std::endl;
    }
};

int main() {
    // Step 1: Create an object using Constructor 1 (sum from 1 to 10)
    SeriesSumCalculator s1(10);
    std::cout << "Series 1 (1 to 10): ";
    s1.displaySeriesParams();

    // Step 2: Create an object using Constructor 2 (sum from 5 to 15, step 1)
    SeriesSumCalculator s2(5, 15);
    std::cout << "Series 2 (5 to 15, step 1): ";
    s2.displaySeriesParams();

    // Step 3: Create an object using Constructor 3 (sum from 2 to 20, step 3)
    SeriesSumCalculator s3(2, 20, 3);
    std::cout << "Series 3 (2 to 20, step 3): ";
    s3.displaySeriesParams();

    // Step 4: Demonstrate error handling (invalid limit for Constructor 1)
    SeriesSumCalculator s4(-5);
    std::cout << "Series 4 (invalid limit): ";
    s4.displaySeriesParams();

    // Step 5: Demonstrate error handling (invalid step for Constructor 3)
    SeriesSumCalculator s5(1, 10, -2);
    std::cout << "Series 5 (invalid step): ";
    s5.displaySeriesParams();

    return 0;
}