双向链表的建立、查找、插入、删除

1、/*双链表的操作:查询、删除、显示、插入。*双向链表克服单向链表向前查找结点需要执行时间O(n)的缺点*2008.1.17*/#include#include#include#defineN10typedefstructnode*ptNode;structnodecharname20;ptNodelLink,rLink;/*双链表的结构定义*/*双链表的创建*/ptNodeCreat(intn)ptNodehead,ptr,newnode;inti;if(head=(ptNode)malloc(sizeof(node)=NULL)printf(cannotfindspace!n);exit(0

2、);head-name0=0;/头结点初始化head-lLink=NULL;head-rLink=NULL;ptr=head;for(i=0;irLink=newnode;/连接新结点printf(Pleaseinputthe%dmansname:,i+1);scanf(%s,newnode-name);newnode-lLink=ptr;/定义newnode的连接关系newnode-rLink=NULL;ptr=newnode;/endforhead-lLink=newnode;ptr-rLink=head;return(head);/*查找名字的位置*/ptNodeSearch(ptNod

3、ehead,char*pEle)ptNodeptr;char*pTemp;ptr=head-rLink;while(ptr!=head)/以是否回到头结点为结束条件pTemp=ptr-name;/pTemp暂存结点的名字地址if(strcmp(pTemp,pEle)=0)return(ptr);elseptr=ptr-rLink;指向下一结点printf(cannotfinddata!n);returnNULL;/在选定名字前插入voidInsert(ptNodehead,char*prior,char*insertEle)ptNodeptr,newnode;if(ptr=Search(hea

4、d,prior)=NULL)printf(Cantfindthedatatoinsert!n);exit(0);if(newnode=(ptNode)malloc(sizeof(node)=NULL)printf(Cantarrangememoryspace!n);exit(0);strcpy(newnode-name,insertEle);给新结点加载值newnode-lLink=ptr-lLink;前指针指向前结点，先处理以新结点为中心前后关系newnode-rLink=ptr;新结点后指针指向定位结点(ptr-lLink)-rLink=newnode;/前结点的由指针指向新结点ptr-l

5、Link=newnode;/*打印输出*/voidPrint(ptNodehead)ptNodeptr;ptr=head-rLink;printf(nNowthedoublelistis:n);while(ptr!=head)printf(%s,ptr-name);ptr=ptr-rLink;printf(n);/*删除*/voidDelete(ptNodeptr)(ptr-rLink)-lLink=ptr-lLink;/(ptr-rLink)-lLink下一结点的左指针被赋前指针(ptr-lLink)-rLink=ptr-rLink;free(ptr);/*主函数*/voidmain(voi

6、d)intnumber;charstudName20;charinsertName20;ptNodehead,searchpoint;number=N;puts(Pleaseinputthesizeofthelist:);scanf(%d,&number);head=Creat(number);Print(head);printf(nPleaseinputthenamewhichyouwanttofind:n);scanf(%s,studName);searchpoint=Search(head,studName);printf(thenameyouwanttofindis:%sn,searchpoint-name);Delete(searchpoint);Print(head);printf(Beforewhichelementdoyouwanttoinsert:n);scanf(%s,studName);printf(Enterthestu