qfedu-cpp-level/day4/homework/h6_2.cpp

#include <iostream>

class ArrayList
{
private:
    int *elements; // 存储元素的数组
    int capacity;  // 数组的容量
    int count;     // 当前元素的数量

public:
    ArrayList()
    {
        capacity = 10; // 初始容量为10
        elements = new int[capacity];
        count = 0;
    }

    ~ArrayList()
    {
        delete[] elements;
    }

    void add(int value)
    {
        if (count == capacity)
        {
            // 如果数组已满，扩展容量为原来的两倍
            int newCapacity = capacity * 2;
            int *newElements = new int[newCapacity];
            for (int i = 0; i < count; i++)
            {
                newElements[i] = elements[i];
            }
            delete[] elements;
            elements = newElements;
            capacity = newCapacity;
        }
        elements[count] = value;
        count++;
    }

    void remove(int index)
    {
        if (index >= 0 && index < count)
        {
            for (int i = index; i < count - 1; i++)
            {
                elements[i] = elements[i + 1];
            }
            count--;
        }
    }

    int get(int index)
    {
        if (index >= 0 && index < count)
        {
            return elements[index];
        }
        return -1; // 返回一个特殊值表示索引无效
    }

    void print()
    {
        for (int i = 0; i < count; i++)
        {
            std::cout << elements[i] << " ";
        }
        std::cout << std::endl;
    }

    int size()
    {
        return count;
    }

    void sort(bool reversed = false)
    {
        for (int i = 0; i < count - 1; i++)
        {
            for (int j = 0; j < count - i - 1; j++)
            {
                if (reversed)
                {
                    if (elements[j] < elements[j + 1])
                    {
                        int temp = elements[j];
                        elements[j] = elements[j + 1];
                        elements[j + 1] = temp;
                    }
                }
                else
                {
                    if (elements[j] > elements[j + 1])
                    {
                        int temp = elements[j];
                        elements[j] = elements[j + 1];
                        elements[j + 1] = temp;
                    }
                }
            }
        }
    }
};

int main()
{
    ArrayList list;

    list.add(5);
    list.add(2);
    list.add(8);
    list.add(1);

    std::cout << "Original list: ";
    list.print();

    std::cout << "Size: " << list.size() << std::endl;

    std::cout << "Element at index 2: " << list.get(2) << std::endl;

    list.remove(1);

    std::cout << "After removing element at index 1: ";
    list.print();

    std::cout << "Sorted list in ascending order: ";
    list.sort();
    list.print();

    std::cout << "Sorted list in descending order: ";
    list.sort(true);
    list.print();

    return 0;
}