/// @file
/// @brief Task1: "single-file" excutable C++ program

#include <iostream>
#include <vector>

/// @brief Calculate the sum of all integer values in a std::vector<std::vector<int>>
/// @param data A vector of vectors containing the values to be summed
/// @return Sum of all values in data
double sum(const std::vector<std::vector<int>>& data) {
    double sum = 0;
    for (const auto& row : data) {
        for (const auto& value : row) {
            sum += value;
        }
    }
    return sum;
}

/// @brief main function (entry point for executable) conducting the following tasks in this order
/// - create and prepare a local variable of type std::vector<std::vector<int>>
///   holding 9 int values in this arrangement:
///   1, 2, 3
///   4, 5, 6
///   7, 8, 9
/// - call your function 'sum' and provide the prepared variable as argument to the call
/// - capture the result of your function call in a local variable and print it to the console
int main() {
    std::vector<std::vector<int>> data = {
        {1, 2, 3},
        {4, 5, 6},
        {7, 8, 9}
    };
    double result = sum(data);
    std::cout << "Sum: " << result << std::endl;
    return 0;
}