带头节点的线性链表类型[原创]
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/*========带头节点的线性链表类型=========*/
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/*=======================================*/
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/*===============包含头文件以及类型定义==============*/
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#include <stdio.h>
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#include <malloc.h>
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#define NULL 0
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#define NODE_NUM 10
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typedef struct lnode{
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char data;
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struct lnode *next;
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}*link,*position;
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typedef struct{
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link head,tail;
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int len;
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}linklist;
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/*======================================================*/
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/*=======一些在其他函数定义中会调用的函数===============*/
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/*======================================================*/
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int compare(char a,char b){ /*---compare---比较两个元素的大小关系*/
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return a-b;
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}
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int visit(link p){
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if(p->data>=65&&p->data<=97)/*---visit---判断结点的元素是否为大写元素*/
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return 1;
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else
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return 0;
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}
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int length(link s){ /*---length---求链的长度*/
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int i=0;/*i不赋初值,编译错误“可能在i定义以前使用了它在length函数中”*/
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link p=NULL;
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p=s;
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while(p->next!=NULL){
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p=p->next;
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i++;
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}
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return i;
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}
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void print(linklist l){ /*---print---在屏幕上输出链表的所有元素*/
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link p=NULL;
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p=l.head;
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if(!p->next){
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printf("\nThe linklist is empty.\n\n");
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return ;
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}
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printf("The list:");
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while(p){
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printf("%c-",p->data);
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p=p->next;
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}
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}
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/*======================================================*/
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/*==========对带头结点的单链线性表进行操作的函数的定义==================*/
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/*======================================================*/
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position makenode(char e){ /*---分配由p指向的结点并赋值为e---*/
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link p=NULL;
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p=(link)malloc(sizeof(struct lnode));
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/*---struct lnode 才能表示一个结构体类型并可用于分配空间的元素类型定义-*/
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if(p){
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p->data=e;
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p->next=NULL;
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}
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else return;
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return p;
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}
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void freenode(link p){ /*---释放p所指向的结点-*/
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free(p);
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}
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int initlist(linklist *l){ /*---构造一个由l指向的空的线性表-*/
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l->head=makenode('L');
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l->head->next=NULL;/*不是l->head=NULL*/
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l->tail=l->head;
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l->len=0;
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return 1;
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}
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position priorpos(linklist l,link p){ /*---返回p所指结点的直接前驱的位置-*/
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link q;
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q=l.head;
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if(q->next==p) return 0;
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while(q->next!=p) q=q->next;
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return q;
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}
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int insfirst(linklist *l,link s){ /*---将s指向的结点插入线性链表的第一个结点之前-*/
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s->next=l->head->next;
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if(!l->head->next) l->tail=s;/*当向一个空的线性表执行该操作时*/
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l->head->next=s;
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l->len++;
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}
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int append(linklist *l,link s){ /*---将指针s所的一串结点链接在线性表L的最后一个结点-*/
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link q;
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q=l->head;
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if(!l->tail){/*考虑到链表为空的情况*/
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l->head->next=s;
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while(q->next) q=q->next;/*尾结点的处理*/
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l->tail=q;
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}
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l->tail->next=q=s;
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while(q->next) q=q->next;/*不能忘了对尾结点的处理*/
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l->tail=q;
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l->len+=length(s);
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}
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position delfirst(linklist *l,link q){ /*---删除表中第一个结点并以q返回-*/
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if(!l->head->next){
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printf("\nThe linklist is empty,can not delete..\n");
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return 0;
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}
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q=l->head->next;
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l->head->next=l->head->next->next;
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return q;
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}
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position remonode(linklist *l,link q){ /*---删除线性表l中的尾结点-*/
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if(!l->tail){
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printf("\nthe linklist is empty,can not remonde..\n");
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return 0;
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}
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q=l->tail; /*用书上函数名remove时,编译错误“调用参数个数出错”*/
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l->tail=priorpos(*l,q);
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l->tail->next=NULL;
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return q;
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}
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int insbefore(linklist *l,link p,link s){ /*---将s所指向结点插入在p所指结点之前-*/
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link q;
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q=priorpos(*l,p);
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s->next=p;
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q->next=s;
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}
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int insafter(link p,link s){ /*---将s所指向结点插入在p所指结点之后-*/
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s->next=p->next;
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p->next=s;
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}
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int setcurelem(link p,char e){ /*---用e更新p所指向的当前结点-*/
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p->data=e;
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}
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char getcurelem(link p){ /*---返回p所指结点中元素的值-*/
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return p->data;
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}
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int listempty(linklist l){ /*---若线性表为空表则返回1,否则返回0-*/
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if(l.head==l.tail) return 1;
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return 0;
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}
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int listlength(linklist l){ /*---返回线性表中元素个数-*/
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return l.len;
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}
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position gethead(linklist l){ /*---返回线性表l中头结点的位置-*/
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return l.head;
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}
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position getlast(linklist l){ /*-----返回线性表l中最后一个结点的位置-------*/
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return l.tail;
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}
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position nextpos(link p){ /*-----返回p所指结点的直接后继的位置-------*/
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link q;
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q=p->next;
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return q;
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}
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position locatepos(linklist l,int i,link p){ /*-----用p返回线性表l中第i个结点的位置,并返回ok-------*/
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p=l.head;
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if(i<=0||i>listlength(l)) return 0;
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while(i){
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p=p->next;
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i--;
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}
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return p;
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}
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int locatelem(linklist l,char e){ /*----返回表中第一个与e满足一定函数关系的结点次序位置--------*/
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int i=0;
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link p;
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p=l.head->next;
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while(compare(p->data,e)&&p){
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p=p->next;
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++i;
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}
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if(!p){/*考虑到查找不到指定元素的情况*/
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printf("\nthere's no '%c' in this linklist.",e);
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return 0;
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}
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return i;
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}
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int listraverse(linklist l){ /*----用一个函数遍历表中所有结点-------*/
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link p;
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p=l.head;
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while(!visit(p)) p=p->next;
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if(p!=l.tail) return 0;
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}
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int clearlist(linklist*l){ /*----?------将线性表l置为空表,并释放原链表的结点?*/
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link p;
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p=(*l).tail;
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while(p!=(*l).head){
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p=priorpos(*l,p);
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freenode(p->next);
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}
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freenode((*l).head);
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}
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int destroylist(linklist *l){ /*----------销毁由l指向的线性表---------*/
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link p;
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p=(*l).tail;
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while(p!=(*l).head){
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p=priorpos(*l,p);
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freenode(p->next);
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}
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freenode((*l).head);
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}
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/*=======================================================*/
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/*==================主函数部分===================*/
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/*=======================================================*/
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main(){
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int i;
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char temp='a';
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linklist *l,*la=NULL,*lb,*lc=NULL;
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link s,s_nodes,q,p,n;
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initlist(l);
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/*调用初始化函数,构造一个由l指向的线性链表*/
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printf("l->head->data:%c ",l->head->data);
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print(*l);
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for(i=1;i<=5;i++){
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s=makenode(temp++);/*每次插入结点都要重新分配空间,否则无限循环*/
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insfirst(l,s);
292
/*将s指向的结点插入在以(*l).head为头结点的链表的第一个元素之前*/
293
}
294
printf("insfirst(l,s)*5, ");
295
print(*l);
296
297
s_nodes=s=makenode(temp++);/*_1_*/
298
printf("\ns_nodes:");
299
for(i=1;i<=NODE_NUM;i++){
300
s->next=makenode(temp++);/*_2_*/
301
printf("%c ",s->data);
302
s=s->next;
303
}/*构造了一串由s_nodes指向的链,并为其中的数据项赋值*/
304
305
append(l,s_nodes);
306
/*将由s_nodes指向的一串结点附加到l指向的链表的后面*/
307
printf("\nappend(l,s_nodes), ");
308
print(*l);
309
310
q=delfirst(l,q);/*---*/
311
/*删除以(*l).head为头结点的链表中的第一个结点并以q返回*/
312
printf("\ndelfirst(l,q), ");
313
print(*l);
314
printf("\nthe deleted element:%c",q->data);
315
316
q=remonode(l,q);
317
/*删除l指向的线性表的尾结点并以q返回*/
318
printf("\nremonode(l,q), ");
319
print(*l);
320
printf("\nthe removed element:%c\n",q->data);
321
322
323
p=l->head;
324
for(i=1;i<=5;++i){
325
p=p->next;
326
}/*移动指针p使其指向链表中的第六个结点*/
327
printf("\np->data:%c, ",p->data);
328
329
s=makenode(temp++);
330
printf("s->data:%c",s->data);
331
insbefore(l,p,s);
332
/*将s指向的结点插入到p指向的结点之前*/
333
printf("\ninsbefore(l,p,s), ");
334
print(*l);
335
336
337
printf("\np->data:%c, ",p->data);
338
s=makenode(temp++);
339
printf("\ns->data:%c",s->data);
340
insafter(p,s);
341
/*将s指向的结点插入到p指向的结点之后*/
342
printf("\ninsafter(p,s),");
343
print(*l);
344
345
setcurelem(p,temp++);
346
/*将p指向的结点的数据项赋值为temp*/
347
printf("\np->data:%c, ",p->data);
348
printf("setcurelem(p,temp++),");
349
print(*l);
350
351
n=s;
352
printf("\ncurrent element:%c\n",getcurelem(n));
353
/*在printf函数中调用getcurelem函数,返回n指向的结点的值*/
354
printf("the listlinks'length:%d\n",listlength(*l));
355
/*在pringf函数中调用listlength函数,返回当前链表的元素个数*/
356
357
printf("priorpos(list,p):%c\n",priorpos(*l,p)->data);
358
/*返回p所指结点的直接前驱的位置*/
359
360
printf("\nnextpos(p):%c\n",nextpos(p)->data);
361
/*返回p所指结点的直接后继的位置*/
362
363
print(*l);
364
printf("\nthe element 'e' located at position %d\n",locatelem(*l,'e'));
365
/*返回l所指向的链表中元素值为e的结点的位置*/
366
printf("the element 'i' located at position %d\n",locatelem(*l,'i'));
367
/*返回l所指向的链表中元素值为e的结点的位置*/
368
369
p=locatepos(*l,6,p);
370
printf("the 6th element:%c",p->data);
371
372
if(!listraverse(*l))
373
printf("\nthere are all Lowercase letters\n");
374
/*判断l指向的链表中是否全都不是大写字母*/
375
376
377
/*=========表间操作=========*/
378
379
380
381
382
383
getch();
384
}
385
386
387
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2
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3
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4
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5
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6
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7
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8
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9
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10
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11
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12
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13
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14
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15
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16
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17
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18
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19
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20
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21
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22
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23
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24
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25
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26
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27
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28
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29
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30
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31
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32
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33
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34
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35
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36
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37
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38
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39
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40
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41
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42
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43
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44
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45
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46
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47
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48
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49
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50
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51
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52
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53
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54
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55
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56
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57
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58
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59
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60
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61
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62
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63
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64
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65
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66
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67
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68
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69
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70
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71
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72
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73
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74
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75
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76
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77
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78
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79
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80
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81
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82
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88
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89
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90
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91
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93
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94
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95
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96
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97
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98
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101
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111
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112
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336
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337
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338
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339
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340
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341
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342
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343
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344
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345
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346
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347
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348
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349
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350
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351
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352
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353
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354
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355
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356
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357
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358
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359
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360
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361
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362
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363
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364
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365
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366
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367
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368
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369
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370
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371
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372
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373
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374
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375
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376
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377
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378
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379
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380
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381
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382
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383
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384
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385
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386
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387
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