C语言各种链表操作(创建、打印、删除、插入、反转)

#include <stdio.h>

#include <stdlib.h>

#define STU_NUM 4

//define a student struct variable

struct Student{

int num;

char name[20];

float score;

struct Student* next;

};

//Create function: creat a new list

//Return: the struct Student list header

struct Student* creatlist(int n)

{

int i = 0;

struct Student *head=NULL;

struct Student *p1=NULL, *p2=NULL;

for (i = 1; i <= n; ++i)

{

p2 = (struct Student*)malloc(sizeof(struct Student));

scanf_s("%ld %s %f",&p2->num,p2->name,20,&p2->score);

if (1 == i)

{

head = p2;

p1 = p2;

}

else

{

p1->next = p2;

p1 = p2;

}

}

p1->next = NULL;

return (head);

}

void printlist(struct Student* head)

{

struct Student *p;

p = head;

while (p != NULL)

{

printf("\nNum:%-ld\tName:%-10s\tscore:%-5.2f\n",p->num,p->name,p->score);

p = p->next;

}

}

//delete one member from the list

//return deleted list

struct Student* deletlist(struct Student *head, int n)

{

int i = 0;

struct Student* p = NULL;

struct Student* d = NULL;

p = head;

if (head == NULL)

{

return (struct Student*)-1;//the list is null!

}

if ((head != NULL) && (1 == n))

{ //if delete head list

d = p;

p = p->next;

free(d);

//*head = *p;

//此处非常关键： 指针做形参（parameter）时，只有当改变了指针的内容时 \

//才会改变实参(argument)的值！！！！！！！

//head = p;
//这样是永远也改变不了实参的值的！！

}

else

{

for (i = 1; i < n - 1; ++i)

{//find the number of n-1 member

if (p != NULL)

{

p = p->next;

}

else

return (struct Student*)-1;//error

}

d = p->next; //find the number n member

if (p->next != NULL)

{

p->next = p->next->next;

//*head = *p;

free(d);

}

else

return (struct Student*)-1;//the number n is not exist

}

return (p);

}

//function realize insert a element into a list

//return the inserted new list

struct Student *insertlist(struct Student* head, struct Student* stu, int n)

{

int i = 0;

struct Student *pMove = NULL;

struct Student *pTemp = NULL;

pMove = head;

pTemp = stu;

if (NULL == head)

{

return (struct Student*)-1;//the list is null!

}

if (1 == n)

{//insert struct Student stu before the list head

pTemp->next = pMove;

return (pTemp);

}

else

{

for (i = 1; i < n - 1; ++i)

{//to find the number n-1 element

if (pMove != NULL)

pMove = pMove->next;

else

return (struct Student*)-1;//n is beyond the list number

}

if (pMove->next != NULL)

{//the insert position is not the rear of list

pTemp->next = pMove->next;

pMove->next = pTemp;

}

else

{

pMove->next = pTemp;

pTemp->next = NULL;

}

return (head);

}

}

//Realize the function of revease the list

struct Student* reverselist(struct Student* head)

{

int nCount = 0;

struct Student *plast = NULL;

struct Student *pPenult = NULL;

struct Student *newHead = NULL;

if (NULL == head->next)

{//only one element in list

return head;

}

pPenult = head;

while (head->next)

{

//traverse to go the last but one elements

while (pPenult->next->next != NULL)

{

pPenult = pPenult->next;

}

plast = pPenult->next;//find the last element of list

plast->next = pPenult;//reverse the last two list

pPenult->next = NULL;//unlock the circle list otherwise: plast->next = pPenult; pPenult->next = last

nCount++;

if (1 == nCount)

newHead = plast;

pPenult = head;

continue;

}

nCount = 0;

return newHead;

}

int main()

{

struct Student* result = NULL;

struct Student stu = {1007,"Song",76.5};

struct Student* pt;

pt = creatlist(STU_NUM);

printf("After creat a new list:\n");

printlist(pt);

result = deletlist(pt, 1);

printf("After delete one element in list:\n");

printlist(result);

pt = insertlist(result, &stu, 4);

printf("After reinsert one element in list:\n");

printlist(pt);

result = reverselist(pt);

printf("After reverse the list:\n");

printlist(result);

return 0;

}

运行结果：