数据结构与GDI+的碰撞(C# VS 2008)之Sequence

2014年5月4日星期日

上次将数据结构Bag呈现了一下，后面又学了一个和Bag类似的结构Sequence。

1）  不同于Bag的随意，Sequence有一个current属性指向当前要操作的位置，如果current属性不可用的话，将current属性和used属性置成一样；

2）  插入是，分为insert()方法和attach()方法。Insert()方法是将元素插入到current索引的前一个位置，当current属性不可用时，插入到第一个元素；attach()方法是将元素插入到current索引的后一个位置，当current属性不可用时，插入到最后一个元素；

3）  不管是insert()和attach()插入，都涉及到元素的移动。需要使用到shiftItemsAfterward()方法和shiftItemsForeward()方法，将元素向后移动和向前移动；

4）  删除也是删除当前current指向的元素，若current不可用，则删除最后一个元素

5）  travel()遍历的时候，使用内部迭代。主要依靠四个成员方法

start()：将current属性指向第一个元素

isItem()：判断current属性指向的是否为合法的元素

advance()：将current属性向后移动,

current()：取得current属性指向的元素

1.      数据结构Sequence的基本实现，Sequence.cs文件如下：

// FILE://DataStructure_Sequence.cs
// CLASS IMPLMENT: class Sequence, insert item in the firstone, and
// delete from the last one
//
// CONSTRUCTORS for class Sequence
// Sequence():
//   Postcondition:default constructor, generate an instance of the sequence class
//   and the capacityof the sequence class is 30
//
// Sequence(sequence_size size):
//   Postcondition:generate an instance of the sequence class, and the capacity is
//   decided by theparameter users provide
//
// MODIFICATION MEMBER METHODS for class Sequence
// void shiftItemsForeward(int indexFrom):
//   Postcondition:shift all items forehead one by one from the given index, the first item willlose
//
// void shiftItemsAfterward(int indexFrom):
//   Precondition: thesequence has the enough room
//   Postcondition:shift all items afterward one by one from the given index
//
// bool insert(sequence_type member):
//   Precondition: it'snot beyond the capacity of the sequence
//   Postcondition:insert the item before the current index. if no current index (the currentindex equals the used),
//   insert into thefirst
//
// bool attach(sequence_type member):
//   Precondition: it'snot beyond the capacity of the sequence
//   Postcondition:insert the item after the current index. if on current index,
//   insert into theend
//
// bool removeCurrent():
//   Postcondition:remove the item the current point to
//
// int search(sequence_type target):
//   Postcondition: iffind return the index, otherwise NOT_FOUND(equal -1)
//
// CONST MEMBER METHOD for sequence class (not const now)
// void travel():
//   Postcondition:travel the sequence
//
// int count(sequence_type target):
//   Postcondition: returnhow many times the target has been found, if
//   not found, return0
//
// uint getCapacity():
//   Postcondition:return the capacity of the sequence
//
// int getUsed():
//   Postcondition:return room has been used
//
// sequence_type getByIndex(int index):
//   Postcondition:return the item by the index user provides
//
// ArrayList getAllFoundIndex():
//   Postcondition:return all the indexs have been found
//   during the searchoperation or count operation
//
// void sort():
//   Postcondition:sort all the items in the sequence
//
// void start():
//   Postcondition:make the current point to the first one
//
// sequence_type current():
//   Precondition:  if isItem() is true;
//   Postcondition:return the item the current point to
//
// advance():
//   Postcondition:shift the current afterwards
//
// bool isItem():
//   Postcondition: ifthe place that the current point to is a available item
using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;
// Alias the data type with my own type
using sequence_size = System.UInt32;
using sequence_type