int  delete(nodelink head,char k){
	nodelink p,q;
	q=head;
	p=head->link;
	while(((p->a)!=k)&&p){
		q=q->link;
		p=p->link;
	  }
	if(p){
		q->link=p->link;
		return 1;
		}
	else{
		printf("There is no %c\n",k);
		return 0;
	  }
}

The reason for this error is that delete is an operator in C + +, and the defined delete function conflicts with it.