代码如下：
#include<iostream>
using namespace std;
#define NULL 0
struct student
{
    long num;
    float score;
    student *next;
};
int n;
int main()
{
    student *creat(void);
    student *del(student *,long);
    student *insert(student *,student *);
    void print(student *);
    student *head,*stu;
    long del_num;
    cout<<"input recrds:"<<endl;
    head=creat();
    print(head);
    cout<<endl<<"input the deleted number:";
    cin>>del_num;
    while(del_num!=0)
    {head=del(head,del_num);
    print(head);
    cout<<"input the deleted number:";
    cin>>del_num;
    }
    cout<<endl<<"input the inserted record:";
    stu=new student;
    cin>>stu->num >>stu->score ;
    while (stu->num !=0)
    {head=insert(head,stu);
    print(head);
    cout<<endl<<"input the inserted record:";
    stu=new student;
    cin>>stu->num>>stu->score ;
    }
    return 0;
}
student *creat(void)
{student *head;
student *p1,*p2;
n=0;
p1=p2=new student;
cin>>p1->num >>p1->score ;
head=NULL;
while(p1->num!=0)
{n=n+1;
if(n==1)head=p1;
else p2->next =p1;
p2=p1;
p1=new student;
cin>>p1->num>>p1->score ;
}
p2->next =NULL;
return(head);
}

student *del(student *head,long num)
{
    student *p1,*p2;
    if(head==NULL)
    {cout<<"list null!!!"<<endl;
    return(head);
    }
    p1=head;
    while(num!=p1->num && p1->next!=NULL    )
    {p2=p1;
    p1=p1->next;}
    if(num==p1->num)
    {if(p1==head)
    head=p1->next;
    cout<<"delete:"<<num<<endl;
    n=n-1;
    }
    else cout<<"cannot find "<<num;
    return(head);
}

student*insert(student*head,student *stud)
{student *p0,*p1,*p2;
p1=head;
p0=stud;
if(head==NULL)
{head=p0;p0->next =NULL;}
else
{while((p0->num>p1->num)&&(p1->next !=NULL))
{p2=p1;
p1=p1->next ;
}
if(p0->num<=p1->num)
{if(head==p1)
head=p0;
p0->next =p1;
}
else
{p1->next =p0;
p0->next =NULL;}
}
n=n+1;
return(head);
}
void print(student *head)
{student *p;
cout<<"Now, These"<<n<<"records are:"<<endl;
p=head;
if(head!=NULL)
do
{cout<<p->num<<" "<<p->score <<endl;
p=p->next ;
}while(p!=NULL);
}

不按顺序  是指什么

就是必须先删除第一个才能删除第二个。

    if(num==p1->num)
    {
        if(p1==head)
            head=p1->next;
        cout<<"delete:"<<num<<endl;
        n=n-1;
    }

在删除的时候  只是做了从头开始移动的    并且也没有真正的释放内存

1、代码  写的很差
2、这样使用c++， 完全没有发挥它的优势（封装， 传引用）