using System;

namespace Lesson6_泛型约束练习
{
    #region 单例模式基类
    class Test
    {
        private static Test instance = new Test();
        public int value = 10;
        public static Test Instance
        {
            get
            {
                return instance;
            }
        }
        private Test() { }
    }

    class SingleBase<T> where T : new()
    {
        private static T instance = new T();
        public static T Instance
        {
            get
            {
                return instance;
            }
        }
    }

    class GameManager : SingleBase<GameManager>
    {
        public GameManager()
        {

        }
    }
    #endregion

    #region 利用泛型知识点，仿造ArrayList实现一个不确定数组类型的类 并 实现增删查改的方法
    class ArrayList<T>
    {
        private T[] array;

        private int count;
        public ArrayList()
        {
            count = 0;
            array = new T[16];
        }
        public void Add(T value)
        {
            if (count >= array.Length)
            {
                T[] temp = new T[Capacity * 2];
                for (int i = 0; i < Capacity; i++)
                {
                    temp[i] = array[i];
                }
                array = temp;
            }
            array[count] = value;
            count++;
        }

        public void Remove(T value)
        {
            int index = -1;
            for (int i = 0; i < count; i++)//小于实际数量不小于容量
            {
                if (array[i].Equals(value))//不能写成array[i] == value因为不是所有类型都重载
                {
                    index = i;
                    break;
                }
            }
            if (index != -1)
            {
                for (;index < Count - 1;index++)
                {
                    array[index] = array[index + 1];
                }
                array[Count - 1] = default(T);
                count--;
            }
        }

        public void RemoveAt(int index)
        {
            if (index < 0 || index >= count)
            {
                Console.WriteLine("索引不合法");
                return;
            }
            for (; index < Count - 1; index++)
            {
                array[index] = array[index + 1];
            }
            array[Count - 1] = default(T);
            count--;
        }

        public T this[int index]
        {
            get
            {
                if (index < 0 || index >= count)
                {
                    Console.WriteLine("索引不合法");
                    return default(T);
                }
                return array[index];
            }
            set
            {
                if (index < 0 || index >= count)
                {
                    Console.WriteLine("索引不合法");
                    return;
                }
                array[index] = value;
            }
        }
        /// <summary>
        /// 得容量和实际数量
        /// </summary>
        public int Capacity
        {
            get
            {
                return array.Length;
            }
        }
        public int Count
        {
            get
            {
                return count;
            }
        }
    }
    #endregion
    class Program
    {
        static void Main(string[] args)
        {
            ArrayList<int> array = new ArrayList<int>();
            Console.WriteLine(array.Count);
            Console.WriteLine(array.Capacity);
            array.Add(1);
            array.Add(2);
            array.Add(3);
            Console.WriteLine(array.Count);
            Console.WriteLine(array.Capacity);
            Console.WriteLine(array[1]);
            Console.WriteLine(array[-1]);
            Console.WriteLine(array[5]);
            array.Remove(2);
            Console.WriteLine(array.Count);
            Console.WriteLine("/////////////////");
            for (int i = 0; i < array.Count; i++)
            {
                Console.Write(array[i]);
            }
            Console.WriteLine();
            Console.WriteLine("/////////////////");
            array.RemoveAt(0);
            for (int i = 0; i < array.Count; i++)
            {
                Console.Write(array[i]);
            }
            Console.WriteLine();
            Console.WriteLine("/////////////////");
            array[1] = 555;
            for (int i = 0; i < array.Count; i++)
            {
                Console.Write(array[i]);
            }
        }
    }
}