链表的创建插入删除

#include<iostream>#include<cstdlib>using namespace std;struct node{int data;node *next;};node* creat(){node *head,*tail,*p;int x;head=tail=new node;while(scanf("%d",&x),x!=-1){p=new node;p->data=x;tail->next=p;tail=p;}tail->next=NULL;return head;}void show(node* head){while(head->next!=NULL){head=head->next;printf("%d ",head->data);}puts("");}node* find(node *head,int i){int j;for(j=0;head->next!=NULL,j<i;j++)head=head->next;if(j==i) return head;return NULL;}void insert(node *head,int x,int y){node *n=find(head,x-1);if(n==NULL) exit(1);else {node *m=new node;m->data=y;m->next=n->next;n->next=m;}}void del(node *head,int x){node *n=find(head,x-1);if(n==NULL) exit(2);else{node *m=n->next;if(m==NULL) exit(3);else{n->next=m->next;delete m;}}}int main(){int x,y;node *head=creat();show(head);cin>>x>>y;insert(head,x,y);show(head);cin>>x;del(head,x);show(head);return 0;}