using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace LinearList
{
  public interface IListDS<T>
  {
    int GetLength();
    void Insert(T item, int i);
    void Add(T item);
    bool IsEmpty();
    T GetElement(int i);
    void Delete(int i);
    void Clear();
    int LocateElement(T item);
    void Reverse();
  }
  //順序表類
  class SequenceList<T>:IListDS<T>
  {
    private int intMaxSize;//最大容量事先確定，使用數(shù)組必須先確定容量
    private T[] tItems;//使用數(shù)組盛放元素
    private int intPointerLast;//始終指向最后一個元素的位置
    public int MaxSize
    {
      get { return this.intMaxSize; }
      set { this.intMaxSize = value; }
    }
    public T this[int i]//索引器方便返回
    {
      get { return this.tItems[i]; }
    }
    public int PointerLast
    {
      get { return this.intPointerLast; }
    }
    public SequenceList(int size)
    {
      this.intMaxSize = size;
      this.tItems = new T[size];//在這里初始化最合理
      this.intPointerLast = -1;//初始值設為-1，此時數(shù)組中元素個數(shù)為0
    }
    public bool IsFull()//判斷是否超出容量
    {
      return this.intPointerLast+1 == this.intMaxSize;
    }
    #region IListDS<T> 成員
    public int GetLength()
    {
      return this.intPointerLast + 1;//不能返回tItems的長度
    }
    public void Insert(T item, int i)//設i為第i個元素，從1開始。該函數(shù)表示在第i個元素后面插入item
    {
      if (i < 1 || i > this.intPointerLast + 1)
      {
        Console.WriteLine("The inserting location is wrong!");
        return;
      }
      if (this.IsFull())
      {
        Console.WriteLine("This linear list is full! Can't insert any new items!");
        return;
      }
      //如果可以添加
      this.intPointerLast++;
      for(int j=this.intPointerLast;j>=i+1;j--)
      {
        this.tItems[j] = this.tItems[j - 1];
      }
      this.tItems[i] = item;
    }
    public void Add(T item)
    {
      if (this.IsFull())//如果超出最大容量，則無法添加新元素
      {
        Console.WriteLine("This linear list is full! Can't add any new items!");
      }
      else
      {
        this.tItems[++this.intPointerLast] = item;//表長+1
      }
    }
    public bool IsEmpty()
    {
      return this.intPointerLast == -1;
    }
    public T GetElement(int i)//設i最小從0開始
    {
      if(this.intPointerLast == -1)
      {
        Console.WriteLine("There are no elements in this linear list!");
        return default(T);
      }
      if (i > this.intPointerLast||i<0)
      {
        Console.WriteLine("Exceed the capability!");
        return default(T);
      }
      return this.tItems[i];
    }
    public void Delete(int i)//設i最小從0開始
    {
      if (this.intPointerLast == -1)
      {
        Console.WriteLine("There are no elements in this linear list!");
        return;
      }
      if (i > this.intPointerLast || i < 0)
      {
        Console.WriteLine("Deleting location is wrong!");
        return;
      }
      for (int j = i; j < this.intPointerLast; j++)
      {
        this.tItems[j] = this.tItems[j + 1];
      }
      this.intPointerLast--;//表長-1
    }
    public void Clear()
    {
      this.intPointerLast = -1;
    }
    public int LocateElement(T item)
    {
      if (this.intPointerLast == -1)
      {
        Console.WriteLine("There are no items in the list!");
        return -1;
      }
      for (int i = 0; i <= this.intPointerLast; i++)
      {
        if (this.tItems[i].Equals(item))//若是自定義類型，則T類必須把Equals函數(shù)override
        {
          return i;
        }
      }
      Console.WriteLine("Not found");
      return -1;
    }
    public void Reverse()
    {
      if (this.intPointerLast == -1)
      {
        Console.WriteLine("There are no items in the list!");
      }
      else
      {
        int i = 0;
        int j = this.GetLength() / 2;//結果為下界整數(shù)，正好用于循環(huán)
        while (i < j)
        {
          T tmp = this.tItems[i];
          this.tItems[i] = this.tItems[this.intPointerLast - i];
          this.tItems[this.intPointerLast - i] = tmp;
          i++;
        }
      }
    }
    #endregion
  }
  class Program
  {
    static void Main(string[] args)
    {
    }
  }
}

//基于順序表的合并排序
static private SequenceList<int> Merge(SequenceList<int> s1,SequenceList<int> s2)
{
  SequenceList<int> sList = new SequenceList<int>(20);
  int i = 0;
  int j = 0;
  while(i<=s1.PointerLast&&j<=s2.PointerLast)
  {
    if (s1[i] < s2[j])
    {
      sList.Add(s1[i]);
      i++;
    }
    else
    {
      sList.Add(s2[j]);
      j++;
    }
  }
  if (i > s1.PointerLast)
  {
    while (j <= s2.PointerLast)
    {
      sList.Add(s2[j]);
      j++;
    }
    return sList;
  }
  else//即j>s2.PointerLast
  {
    while (i <= s1.PointerLast)
    {
      sList.Add(s1[i]);
      i++;
    }
    return sList;
  }
}