循环单链表

来源：互联网发布：数据恢复装系统编辑：程序博客网时间：2024/06/07 03:04
循环单链表是单链表的另一种形式，其结构特点链表中最后一个结点的指针域不再是结束标记，而是指向整个链表的第一个结点，从而使链表形成一个环。
形态：
1，链表为空时：
2，链表非空时：
/***********************************************    循环单链表的实现    by Rowandjj    date 2014.4.1***********************************************/#include<IOSTREAM>using namespace std;#define OVERFLOW -1typedef int ElemType;typedef struct _NODE_{    ElemType e;    struct _NODE_ *next;}Node,*pNode,*LinkList_C;/*操作声明*/void InitList(LinkList_C &L);void DestroyList(LinkList_C &L);int ListEmpty(LinkList_C L);int ListLength(LinkList_C L);void PrintList(LinkList_C L);int GetElem(LinkList_C L,int n,ElemType &e);int LocateElem(LinkList_C L,ElemType e);int ListInsert(LinkList_C &L,int n,ElemType e);int ListDelete(LinkList_C &L,int n,ElemType &e);void CreateList(LinkList_C &L,int n);/*****************************************************//*具体实现细节*/void InitList(LinkList_C &L){    L = (pNode)malloc(sizeof(Node));    if(!L)    {        exit(OVERFLOW);    }    L->next = L;}void CreateList(LinkList_C &L,int n){    ElemType e;    if(n <= 0)    {        return;    }    for(int i = 0; i < n; i++)    {        pNode p = (pNode)malloc(sizeof(Node));        if(!p)        {            exit(OVERFLOW);        }        cin>>e;        p->e = e;        p->next = L->next;        L->next = p;    }}int ListDelete(LinkList_C &L,int n,ElemType &e){    pNode p = L,q;    int i = 0;    if(p->next == L || n <= 0)    {        return 0;    }    if(n == 1)    {        q = p->next;        e = q->e;        p->next = q->next;        free(q);            return 1;    }    p = p->next;    while(p!=L && i<n-2)    {        i++;        p = p->next;    }    if(p == L)    {            return 0;    }    if(p->next == L)//注意这里加了一个判断，否则当要删除的位置为链表长度时+1时会报错    {        return 0;    }    q = p->next;    p->next = q->next;    e = q->e;    free(q);    return 1;}int ListInsert(LinkList_C &L,int n,ElemType e){    pNode p = L,q;    int i = 0;    if(n<= 0)    {        return 0;    }    if(p->next == L || n == 1)    {        q = (pNode)malloc(sizeof(Node));        if(!q)        {            exit(OVERFLOW);        }        q->e = e;        q->next = p->next;        p->next = q;                return 1;    }    else    {        p = p->next;        while(p != L && i < n-2)        {            p = p->next;            i++;        }        if(p == L)        {            return 0;        }        q = (pNode)malloc(sizeof(Node));        if(!q)        {            exit(OVERFLOW);        }            q->next = p->next;        p->next = q;        q->e = e;            return 1;    }}int LocateElem(LinkList_C L,ElemType e){    pNode p = L->next;    int i = 1;    if(p == L)    {        return -1;    }    while(p!=L && p->e != e)    {        p = p->next;        i++;    }    if(p == L)    {        return -1;    }    return i;}int GetElem(LinkList_C L,int n,ElemType &e){    //  1<=n<=list_size    pNode p = L->next;    int i = 0;    if(p == L)    {        return 0;    }    if(n == 1)    {        e = p->e;        return 1;    }    while(p!=L && i < n-1)    {        i++;        p = p->next;    }    if(p == L)    {        return 0;    }    e = p->e;    return 1;}void PrintList(LinkList_C L){    pNode p = L->next;    while(p!=L)    {        cout<<p->e<<" ";        p = p->next;    }    cout<<endl;}int ListLength(LinkList_C L){    pNode p = L->next;    int i = 0;    if(p == L)    {        return 0;    }    while(p!=L)    {        i++;        p = p->next;    }    return i;}int ListEmpty(LinkList_C L){    return L->next == L;}void DestroyList(LinkList_C &L){    pNode p,q = L->next;    while(q != L)    {        p = q->next;        free(q);        q = p;    }    free(L);    L = NULL;}
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