尹成老师，关于链表的一些操作（C）

///.h文件

#include <stdio.h>

#include <stdlib.h>

struct student{

int num;

float score;

struct student *pNext;//存储下一个节点的指针

};

typedef struct student ST;

void add(ST **phead, int num, float iscore);

void deleteNode(ST **phead, ST *deletenode);

ST *rev(ST *head);

int getNum(ST *head);

void freeAll(ST *head);

void showall(ST *head);

ST * search(ST*head,int Num);//根据编号查找结点

void change(ST*head, int oldnum, int newnum);

ST *Delete(ST *head, int num);

ST *Headinsert(ST *head, int num,int inum,float iscore);

ST *Endinsert(ST *head, int num, int inum, float iscore);

/// .c ////////////////////////////////////

#include <iostream>

#include <stdlib.h>

#include <string>

#include "linknode.h"

void main()

{

struct student *head = NULL;

add(&head, 1, 70);

add(&head, 2, 80);

add(&head, 3, 70);

add(&head, 4, 80);

add(&head, 5, 70);

/*head = rev(head);*/

/*showall(head);

printf("\nThe Number is of link :%d\n\n\n", getNum(head));

ST *pSearch = search(head, 3);

change(head, 3, 30);

printf("\npSearch = %p, %f\n\n\n", pSearch,pSearch->score);*/

showall(head);

/*head = Delete(head, 6);

showall(head);*/

printf("前插插入之后\n\n\n");

head = Headinsert(head, 4, 13, 100);

showall(head);

printf("后插插入之后\n\n\n");

head = Endinsert(head, 4, 13, 130);

showall(head);

//freeAll(head);

//head = NULL;//一定要注意结点设置为空！!!!

//showall(head);

/*printf("%d, %f\n", head->num, head->score);

printf("%d, %f", head->pNext->num, head->pNext->score);

*/

system("pause");

}

void add(ST **phead, int num, float iscore)

{

if (*phead == NULL)//判断链表是否为空

{

ST *newnode = (ST*)malloc(sizeof(ST));//分配内存

if (newnode == NULL)

{

printf("内存分配失败！");

return;

}

newnode->num = num;

newnode->score = iscore;

newnode->pNext = NULL;

*phead = newnode;

}

else

{

//说明链表不为空

ST *p = *phead;

while (p->pNext != NULL)

{

p = p->pNext;//循环向前

}//p=NULL 就终止循环！

ST *newnode = (ST*)malloc(sizeof(ST));//分配内存

newnode->num = num;

newnode->score = iscore;

newnode->pNext = NULL;

p->pNext = newnode;//连接上

}

}

ST *rev(ST *head)

{

ST *p1, *p2, *p3;

p1 = p2 = p3 = NULL;

if (head == NULL||head->pNext == NULL)

{

return head;//返回头结点，在链表为空的的时候和链表只有一个结点的时候，不用翻转！

}

p1 = head;

p2 = head->pNext;

while (p2 != NULL)

{

p3 = p2->pNext;//布局三个结点；

p2->pNext = p1;

p1 = p2;//指针向前移动，从第二个到最后一个结点

p2 = p3;

}

head->pNext = NULL;//代表链表的结束，设置第一个结点为空！

head = p1;

return head;//改变head,并不会生效，需要返回值赋值生效！

}

void deleteNode(ST **phead, ST *deletenode)

{

}

void showall(ST *head)

{

while (head != NULL)

{

printf("num = %d, score = %f\n", head->num, head->score);

printf("p = %p, p->pNext = %p\n", head, head->pNext);

head = head->pNext;

}

}

void freeAll(ST *head)

{

ST *p1, *p2;

p1 = p2 = NULL;

p1 = head;

while (p1->pNext != NULL)

{

p2 = p1->pNext;

p1->pNext = p2->pNext;//p1存储了p1的下一个结点的地址！然后释放

free(p2);

}

free(head);

//

}

int getNum(ST *head)

{

int i = 0;

while (head != NULL)

{

i++;

head = head->pNext;

}

return i;

}

ST * search(ST*head, int Num)

{

while (head != NULL)

{

if (Num == head->num)

{

return head;//返回当前结点指针地址！

}

head = head->pNext;

}

return NULL;

}

void change(ST*head, int oldnum, int newnum)

{

ST *psearch = search(head, oldnum);

if (psearch == NULL)

{

printf("没有找到！");

}

else

{

psearch->num = newnum;

}

}

ST *Delete(ST *head, int num)

{

ST *p1, *p2;

p1 = p2 = NULL;

p1 = head;

while (p1 != NULL )

{

if (p1->num == num)

{

break;

}

else

{

p2 = p1;//记录当前结点,也就是为了找到被删除结点的前一个结点

p1 = p1->pNext;//继续往前

}

}

if (p1 == head)

{

head = p1->pNext;

free(p1);

p1 = NULL;

}

else

{

p2->pNext = p1->pNext;

free(p1);//释放p1;

p1 = NULL;

}

return head;

}

ST *Headinsert(ST *head, int num, int inum, float iscore)

{

ST *p1, *p2;

p1 = p2 = NULL;

p1 = head;

while (p1 != NULL)

{

if (p1->num == num)

{

break;

}

else

{

p2 = p1; //记录当前结点，也就是为了插入数据时候使用,也就是在P2,p1之间插入数据

p1 = p1->pNext;

}

}

if (head == p1)//头结点

{

ST * newNode = (ST*)malloc(sizeof(ST));

newNode->num = inum;

newNode->score = iscore;

newNode->pNext = head;//newnode指向头结点

head = newNode;//newNode成为头结点

}

else

{

ST * newNode = (ST*)malloc(sizeof(ST));

newNode->num = inum;

newNode->score = iscore;

newNode->pNext = p1;//newnode指向头结点

p2->pNext = newNode;//newNode成为头结点

}

return head;

}

ST *Endinsert(ST *head, int num, int inum, float iscore)

{

ST *p1, *p2;

p1 = p2 = NULL;

p1 = head;

while (p1 != NULL)

{

if (p1->num == num)

{

break;

}

else

{

//p2 = p1; //后插的时候不需要记录

p1 = p1->pNext;

}

}

if (p1->pNext == NULL)//最后一个结点

{

ST *newNode = (ST*)malloc(sizeof(ST));

newNode->num = inum;

newNode->score = iscore;

newNode->pNext = NULL;//newnode指向最后的空

p1->pNext = newNode;

}

else

{

p2 = p1->pNext;

ST *newNode = (ST*)malloc(sizeof(ST));

newNode->num = inum;

newNode->score = iscore;

newNode->pNext = p2;//newnode指向最后的空

p1->pNext = newNode;

}

return head;

}