Problem B: C语言习题 链表建立，插入，删除，输出

Problem B: C语言习题 链表建立，插入，删除，输出

Time Limit: 1 Sec  Memory Limit: 128 MB
Submit: 976  Solved: 505
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Description

编写一个函数creatlink，用来建立一个动态链表。（包含学号和成绩）
编写一个函数printlink，用来输出一个链表。
编写一个函数dellink，用来删除动态链表中一个指定的结点(由实参指定某一学号，表示要删除该学生结点)。
编写一个函数insertlink，用来向动态链表插入一个结点。
编写一个函数freelink，用来释放一个动态链表。

Input

输入多个学生的学号和成绩，建立动态链表，以0 0 结束
输入学号，删除链表中的对应结点
插入两个链表结点

Output

输出的链表

Sample Input

1001 100
1002 95
1005 90
1008 76
0 0
1005
1006 98
1009 99

Sample Output

1001 100.00
1002 95.00
1006 98.00
1008 76.00
1009 99.00

HINT

主函数已给定如下，提交时不需要包含下述主函数



/* C代码 */

int main()

{

    struct student *creatlink(void);

    struct student *dellink(struct student *,long);

    struct student *insertlink(struct student *,struct student *);

    void printlink(struct student *);

    void freelink(struct student *);

    struct student *head,stu;

    long del_num;

    head=creatlink();

    scanf("%ld",&del_num);

    head=dellink(head,del_num);

    scanf("%ld%f",&stu.num,&stu.score);

    head=insertlink(head,&stu);

    scanf("%ld%f",&stu.num,&stu.score);

    head=insertlink(head,&stu);

    printlink(head);

    freelink(head);

    return 0;

}



/* C++代码 */



int main()

{

    student *creatlink(void);

    student *dellink(student *,long);

    student *insertlink(student *,student *);

    void printlink(student *);

    void freelink(student *);

    student *head,stu;

    long del_num;

    head=creatlink();

    cin>>del_num;

    head=dellink(head,del_num);

    cin>>stu.num>>stu.score;

    head=insertlink(head,&stu);

    cin>>stu.num>>stu.score;

    head=insertlink(head,&stu);

    cout<<setiosflags(ios::fixed);

    cout<<setprecision(2);

    printlink(head);

    freelink(head);

    return 0;

}

#include<stdio.h>
#include<stdlib.h>
struct student
{
    long num;
    float score;
    struct student *next;
};
struct student *creatlink(void)
{
    struct student *head;
    struct student *p1,*p2;
    int n=0;
    p1=p2=(struct student*)malloc(sizeof(struct student));
    scanf("%ld%f",&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=(struct student*)malloc(sizeof(struct student));
        scanf("%ld%f",&p1->num,&p1->score);
    }
    p2->next=NULL;
    return(head);
}
struct student *dellink(struct student *head,long num)
{
    struct student *p1,*p2;
    if(head==NULL)
    {
        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;
        else
            p2->next=p1->next;
    }
    return(head);
}
struct student *insertlink(struct student *head,struct student *stud)
{
    struct student *p0,*p1,*p2;
    p1=head;
    p0=(struct student*)malloc(sizeof(struct student));
    *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;
            else
                p2->next=p0;
            p0->next=p1;
        }
        else
        {
            p1->next=p0;
            p0->next=NULL;
        }
    }
    return(head);
}
void printlink(struct student *head)
{
    struct student *p;
    p=head;
    if(head!=NULL)
        do
        {
            printf("%ld %.2f\n",p->num,p->score);
            p=p->next;
        }
        while(p!=NULL);
}
void freelink(struct student *head)
{
    struct student *p,*q;
    p=head;
    if(head!=NULL)
        do
        {
            q=p;
            p=p->next;
            free(q);
        }
        while(p!=NULL);
}

　　

#include<stdio.h>
#include<stdlib.h>
/********************************************************/
typedef struct student
{
    long num;
    float score;
    struct student *next;
}student;
/********************************************************/
student *creatlink(void)//建立链表
{
    student *st=(student *)malloc(sizeof(student)),*pend,*head;//申请内存空间
    scanf("%ld%f",&st->num,&st->score);//输入学生信息
    head=NULL;
    while(st->num!=0)//当输入0 0时结束
    {
        if(head==NULL)
            head=st;//head起个头
        else
            pend->next=st;//指向下一个结点的地址
        pend=st;
        st=(student *)malloc(sizeof(student));//重新申请内存地址
        scanf("%ld%f",&st->num,&st->score);
    }
    pend->next=NULL;
    free(st);//把多申请的那个释放
    return head;//返回首地址，千万别改
}
/********************************************************/
void printlink(student *head)//链表输出
{
    while(head!=NULL)
    {
        printf("%ld %.2f\n",head->num,head->score);
        head=head->next;
    }
}
/********************************************************/
student *dellink(student *head,long del)//删除
{
    student *p1,*p2=head;
    while(p2!=NULL)
    {

        if(del==p2->num)
        {
            p1->next=p2->next;
            //上一个的next指向被删除结点的下一个地址
            //也就是上一个的next的值换成下一个next的值
            break;
        }
        else
        {
            p1=p2;
            p2=p2->next;
        }
    }
    return head;
}
/********************************************************/
student *insertlink(student *head,student *std)//插入
{
    student *p2=head,*p1,*st=(student *)malloc(sizeof(student));//一定要申请新的内存地址
    st->num=std->num;//把值赋给st就可以了，别赋地址
    st->score=std->score;
    st->next=std->next;
    while(p2->next!=NULL)
    {
        if(p2->num<st->num&&st->num<p2->next->num)
        //简单的排一下序
        {
            p1=p2->next;
            p2->next=st;
            st->next=p1;
            return head;
            //插进去了就退出吧
        }
        else
            p2=p2->next;
    }
    if(p2->next==NULL)//当在最后插入结点时
    {
        p2->next=st;
        st->next=NULL;//别忘了
    }
    return head;
}
/********************************************************/
void freelink(student *head)//释放链表
{
    student *p1=head,*p2;
    while(p1!=NULL)//排着释放
    {
        p2=p1->next;
        free(p1);
        p1=p2;
    }
}
int main()

 {

     struct student *creatlink(void);

     struct student *dellink(struct student *,long);

     struct student *insertlink(struct student *,struct student *);

     void printlink(struct student *);

     void freelink(struct student *);

     struct student *head,stu;

     long del_num;

     head=creatlink();

     scanf("%ld",&del_num);

     head=dellink(head,del_num);

     scanf("%ld%f",&stu.num,&stu.score);

     head=insertlink(head,&stu);

     scanf("%ld%f",&stu.num,&stu.score);

     head=insertlink(head,&stu);

     printlink(head);

     freelink(head);

     return 0;

 }

　　

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef struct student
 {
    long num;
    float score;
    struct student *next;
 }student;
 student *creatlink(void)
 {
     student *head = NULL;
     student *last , *p ;
     p =(student *)malloc(sizeof(student));
     scanf("%ld%f",&p->num,&p->score);
     while(p->num!=0)
     {
         if(head==NULL)
         {
             head=p;
         }
         else
             last->next=p;
         last=p;
         p =(student *)malloc(sizeof(student));
         scanf("%ld %f",&p->num,&p->score);
     }
     last->next=NULL;
     free(p);
     return head;
 }
student *dellink(student *head,long del)
 {
    student *p1,*p2=head;
    while(p2)
    {
        if(del==p2->num)
        {
            p1->next=p2->next;
            free(p2);
            break;
        }
        else
        {
            p1=p2;
            p2=p2->next;
        }
    }
    return head;
 }
void printlink(struct student *head)
{
    while(head!=NULL)
    {
        printf("%ld %.2f\n",head->num,head->score);
        head=head->next;
    }
}
void freelink(struct student *head)
{
    student *p1=head;
    student *p2;
    while(p1)
    {
        p2=p1->next;
        free(p1);
        p1=p2;
    }
}
student *insertlink(student *head,student *stu)
{
    student *p =head ;
    student *pe ; //记录前驱
    student *pLast =NULL ; //指向尾节点的;
    student *newbase = (student *)malloc( sizeof(student));
    if(newbase==NULL) //分配内存失败
        exit(-1);
    newbase->num =stu->num ;
    newbase->score =stu->score ;
    newbase->next=NULL;
    while(p->next!=NULL)
    {
        p= p->next ;
    }
    pLast = p ;
    p = head ;//重新指向

        if(head->num>newbase->num)
        {
            /*作为头结点的*/
            newbase->next =head;
            head =newbase ;

        }
        else if(head->num < newbase->num && newbase->num < pLast->num)
        {
            /*在中间插入*/
            while((p->num<=newbase->num)&&(p->next!=NULL))
            {
                pe= p ;
                p=p->next ;

            }
            pe->next =newbase ;
            newbase->next = p;
        }
        else
        {
            /*尾*/
            pLast->next =newbase ;
        }

        return head ;
}
int main()

{

    struct student *creatlink(void);

    struct student *dellink(struct student *,long);

    struct student *insertlink(struct student *,struct student *);

    void printlink(struct student *);

    void freelink(struct student *);

    struct student *head,stu;

    long del_num;

    head=creatlink();

    scanf("%ld",&del_num);

    head=dellink(head,del_num);

    scanf("%ld%f",&stu.num,&stu.score);

    head=insertlink(head,&stu);

    scanf("%ld%f",&stu.num,&stu.score);

    head=insertlink(head,&stu);

    printlink(head);

    freelink(head);

    return 0;

}