第二章線性表

interface IList<T>
    {
        void Clear();
        bool IsEmepty();
        int GetLength();
        T GetElem(int index);
        T this[int index] { get;}
        int Index(T Elem);
        void Insert(int index, T elem);
        void Add(T elem);
        void Delete(int index);
        
    }      

class List<T> : IList<T>
    {
        private T[] data;  //定義一個T類型數組
        private int count; //數組的長度(元素個數)

        public List()
        {

        }
        public List(int size) //配置設定記憶體大小
        {
            data=new T[size];
            count = 0;
        }

        /// <summary>
        /// 通過牽引器擷取T
        /// </summary>
        /// <param name="index"></param>
        /// <returns></returns>
        public T this[int index]
        {
            get
            {
                if (count==0)
                {
                    Console.WriteLine("空表不存在資料");
                }

                if (0<=index&&index<=count-1)
                {
                    return data[index];
                }
                else
                {
                    Console.WriteLine("index超出範圍");
                }
                return default(T);
            }
        }


        public void Add(T elem)
        {
            if (count>data.Length)
            {
                Console.WriteLine("數組容量溢出");
            }
            else
            {
                data[count] = elem;
                count++;
            }
           
        }

        public void Clear()
        {           
            count = 0;//空表data.length=0
        }

        public void Delete(int index)
        {
            if (count==0)
            {
                Console.WriteLine("空表删除不了");
                return;
            }

            if (index<0||index>=count)
            {
                Console.WriteLine("index{0}位置不合法，删除不了",index);
                return;
            }

            if (index==count-1)
            {
                System.Collections.Generic.List<T>newList=new System.Collections.Generic.List<T>(data);
                newList.RemoveAt(index);
                data = newList.ToArray();
                count--;
                return;
            }

            for (int i = index+1; i < count; i++)
            {
                data[i-1] = data[i ];
            }

            count--;
        }

        public T GetElem(int index)
        {
            return this[index];
        }

        public int GetLength()
        {
            return count;
        }

        public int Index(T Elem)
        {
            if (count<=0)
            {
                return -1;
                Console.WriteLine("空表");
            }
            else
            {
                int temp=0;
                for (int i = 0; i < data.Length; i++)
                {
                    if (data[i].Equals(Elem))
                    {
                        temp = i;
                    }        
                }

                return temp;
            }
        }

        public void Insert(int index, T elem)
        {
            if (count > data.Length)
            {
                Console.WriteLine("數組容量溢出無法插入");
                return;
            }
            if (index<0||index>count)
            {
                Console.WriteLine("index{0}插入位置不合法",index);
                return;
            }

            if (index==count )
            {
                data[index] = elem;
                count++;
                return;
            }

            for (int i = count-1; i>=index; i--)
            {
                data[i+1] = data[i];
            }

            data[index] = elem;
            count++;
        }

        public bool IsEmepty()
        {
            return count == 0;
        }
    }      

class Program
    {
        static void Main(string[] args)
        {         

            IList<int> sum=new List<int>(5);
            Console.WriteLine(sum.IsEmepty());       
            Console.WriteLine();
            Console.WriteLine(sum.GetLength());
            sum.Add(10);  
            sum.Add(20);
            sum.Add(30);
            sum.Add(40);
            sum.Add(50);
            Console.WriteLine("sum.GetLength()"+sum.GetLength());
            Console.WriteLine("sum.GetElem()" + sum.GetElem(6));
            for (int i = 0; i < sum.GetLength(); i++)
            {
                Console.Write(sum[i]+"   ");
            }
            Console.WriteLine();
            sum.Delete(3);

            for (int i = 0; i < sum.GetLength(); i++)
            {
                Console.Write(sum[i] + "   ");
            }

            Console.WriteLine();
            sum.Insert(4,100);
            for (int i = 0; i < sum.GetLength(); i++)
            {
                Console.Write(sum[i] + "   ");
            }

            Console.ReadKey();
        }
    }