//定义一个数组类模版，然后以它为基类模板，如何定义一个派生类模板？
#include <iostream>
#include <vector>
// 基类模板：数组类模板
template<typename T>
class Array {
protected:
    std::vector<T> data;
public:
    Array(int size) : data(size) {}
    void set(int index, const T& value) {
        data[index] = value;
    }
    T get(int index) const {
        return data[index];
    }
    int size() const {
        return data.size();
    }
};
// 派生类模板：增强数组类模板
template<typename T>
class EnhancedArray : public Array<T> {
public:
    EnhancedArray(int size) : Array<T>(size) {}
    // 新增函数：求和
    T sum() const {
        T sum = 0;
        for (const auto& element : this->data) {
            sum += element;
        }
        return sum;
    }

    // 新增函数：平均值
    double average() const {
        if (this->data.empty()) {
            return 0.0;
        }
        T sum = this->sum();
        return static_cast<double>(sum) / this->data.size();
    }
};
int main() {
    EnhancedArray<int> arr(5);
    for (int i = 0; i < 5; ++i) {
        arr.set(i, i + 1);
    }
    std::cout << "Array elements: ";
    for (int i = 0; i < arr.size(); ++i) {
        std::cout << arr.get(i) << " ";
    }
    std::cout << std::endl;
    std::cout << "Sum: " << arr.sum() << std::endl;
    std::cout << "Average: " << arr.average() << std::endl;
    return 0;
}