链式线性表

2013-03-23    00:14:39

        上学期的时候就大致看了数据结构与算法分析的了，但感觉收获比较少，总结原因是编程实践少了，所以今年趁着老师上课，就多进行一些代码的实践，也准备拿一些ACM的题目来练练。

         中午的时候就将链式表的代码打了一遍，现在贴上来分享。

         为了节省时间，我的注释也相对较少，有不懂得可以提问。

第一个是Link.head，这是一个节点类，是链表中的小单元

#ifndef LINK
#define LINK
//Singly-linked list node

template <class Elem> class Link{
    public:
    Elem element;
    Link *next;
    Link(const Elem& elemval,Link *nextval = NULL)
    {
        element = elemval;
        next = nextval;
    }
    Link(Link *nextval = NULL)
    {
        next = nextval;
    }
};
#endif

第一个，LList头文件，这就是链表的主体，由节点类组成。

//List abstrat class
#ifndef LIST
#define LIST
//Linked list implementation
#include"Link.h"
#include<iostream>
template <class Elem> class LList {
    private:
    Link<Elem> *head;   //Pointer to list header
    Link<Elem> *tail;    //Pointer to list tail
    Link<Elem> *fence;   //Last element on the left side
    int leftcnt;      
    int rightcnt;
    void init()
    {
        fence = tail = head = new Link<Elem>;
        leftcnt = rightcnt = 0;
    }
    void removeall()
    {
        while(head != NULL)
        {
            fence = head;
            head = head->next;
            delete fence;
        }
    }
    public:
    LList(int size = 100)
    {
        init();
    }
    ~LList()
    {
        removeall();
    }
    void clear()
    {
        removeall();
        init();
    }
    bool insert(const Elem& item)
    {
        fence->next = new Link<Elem>(item , fence->next);
        if(tail == fence)
        tail = fence->next;
        rightcnt++;
        return true;
    }
    bool append(const Elem& item)
    {
        tail = tail->next = new Link<Elem>(item,NULL);
        rightcnt++;
        return true;
    }
    bool remove(Elem &item)
    {
        if(fence->next == NULL)
        return false;
        item = fence->next->element;
        Link<Elem> *ltemp = fence->next;
        fence->next = ltemp->next;
        if(tail == ltemp)
        tail = fence;
        delete ltemp;
        rightcnt--;
        return true;
    }
    void setStart()
    {
        fence = head;
        rightcnt += leftcnt;
        leftcnt = 0;
    }
    void setEnd()
    {
        fence = tail;
        leftcnt += rightcnt;
        rightcnt = 0;
    }
    //cost most time n
    void prev()
    {
        if(fence == head)
        return;
        Link<Elem> *ltemp = head;
        while(ltemp->next != fence)
        ltemp = ltemp->next;
        fence = ltemp;
        rightcnt++;
        leftcnt--;
    }
    void next()
    {
        if(fence == tail)
        return;
        fence = fence->next;
        rightcnt--;
        leftcnt++;
    }
    int leftLength()const
    {
        return leftcnt;
    }
    int rightLength()const
    {
        return rightcnt;
    }
    //set the size of left partition to pos
    bool setPos(int pos)
    {
        if(pos < 0 || pos > rightcnt + leftcnt)
        return false;
        fence = head;
        for(int i = 0;i < pos;i++)
        fence = fence->next;
        return true;
    }
    bool getValue(Elem &it)const
    {
        if(rightLength() == 0)
        return false;
        it = fence->next->element;
        return true;
    }
    void print()const
    {
        Link<Elem> *ltemp = head;
        std::cout << "< ";
        while(fence != ltemp)
        {
            std::cout << ltemp->next->element << " ";
            ltemp = ltemp->next;
        }
        std::cout << "| ";
        while(ltemp->next != NULL)
        {
            std::cout << ltemp->next->element << " ";
            ltemp = ltemp->next;
        }
        std::cout << ">\n";
    }
};






#endif

今天还继续进行着算法的工作，等我总结了就跟大家分享。