链表的建立

#ifndef List#include <iostream>using namespace std;struct listNode;typedef int ElementType;typedef struct listNode *PtrToNode;typedef PtrToNode List;typedef PtrToNode Position;#endif//定义链表结构体struct listNode{ElementType data;Position next;};//判断链表是否为空int isEmpty(List head){return head->next==NULL;}//带有头结点的尾部插入法创建链表List creatList(int num){ElementType elem;//链表中存储的元素List head;Position p,s;head=(List)malloc(sizeof(listNode)); //创建头结点p=head;p->next=NULL;//cout<<"请输入第1个元素:"<<"   ";//cin>>elem;cout<<endl;for(int i=0,j=1;i<num;i++,j++){cout<<"请输入第"<<j<<"个元素:"<<"   ";cin>>elem;s=(List)malloc(sizeof(listNode));//创建链表节点s->data=elem;p->next=s;p=s;p->next=NULL;cout<<endl;}return head;}//输出链表void disPlay(List head){if(isEmpty(head)){cout<<"链表不存在";}else{List p;p=head->next;while(p){cout<<p->data<<"   ";p=p->next;}}}int main(){List list;int num=1;cout<<"请输入要存储的元素个数:"<<"   ";cin>>num;list=creatList(num);//建立链表disPlay(list);//打印链表return 0;}