C语言链表插入节点未知错误

Question

想在第0个节点处（最前面）添加一个节点，程序检查了好几遍实在看不出来错误，求大神指点！！

#include<stdio.h>
#include<stdlib.h>
struct node{
	int id,mpoints;
	struct node *next;
};
int main(){
	struct node * creat(struct node * head,int n);
	void print(struct node *head);
	struct node *insert(struct node *head,int pos);

	struct node *head=NULL;
	head=creat(head,5);
	print(head);
	insert(head,0);
	print(head);
	return 0;
}
struct node * creat(struct node * head,int n){//构造节点
	int i;
	struct node *p,*q;
	for(i=1;i<=n;i++){
		q=(struct node*)malloc(sizeof(struct node));
		printf("请输入第%d个会员id和积分：\n",i);
		scanf("%d%d",&q->id,&q->mpoints);
		q->next=NULL;
		if(head==NULL)
			head=q;
		else
			p->next=q;
		p=q;
	}
	return head;
}
void print(struct node *head){//遍历节点
	struct node *p=head;
	printf("id\tmpoints\n");
	while(p!=NULL){
		printf("%d\t%d\n",p->id,p->mpoints);
		p=p->next;
	}
}
struct node *insert(struct node *head,int pos){//指定位置插入节点
	struct node *p,*pNew,*q;
	int i=0;
	pNew=(struct node *)malloc(sizeof(struct node));
	printf("请输入要插入的会员id和积分:\n");
	scanf("%d%d",&pNew->id,&pNew->mpoints);
	if(NULL==pNew)      
	{
      printf("动态内存分配失败！\n");
	  exit(-1);
	}
	if (head==NULL){
		pNew->next=NULL;
		head=pNew;
		return head;
	}
	if(pos<0){
		printf("插入位置有错！\n");
		return head;
	}
	if(pos==0){                    //在最前面插入节点
		pNew->next=head;
		head=pNew;		
		return head;
	}

	p=head;
	while(p!=NULL&&i<pos-1){
		p=p->next;
		++i;
	}
	if(p==NULL){
		printf("插入位置有错！\n");return head;
	}
	q=p->next;
	p->next=pNew;
	pNew->next=q;
	return head;
	
}

 

 

Answer 1

insert(head,0);改成head = insert(head,0);就可以了

你这个函数只能用返回值改变head地址，参数不能