单链表的头插法和尾插法c语言实现

/*单链表的头插法和尾插法c语言实现*/

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#define SIZE 100

/*简单的定义一个链表节点的数据单元*/

typedef struct student_t

{

int num;

char name[SIZE];

struct student_t* pNext;

}studentList, *pStudentList;

/*定义一个全局的静态的链表头节点指针*/

static pStudentList g_pstStudentList = NULL;

/*创建一个学生信息的链表节点*/

pStudentList createaOneStudentListNode()

{

pStudentList pNewNode = NULL;

pNewNode = (pStudentList)malloc(sizeof(studentList));

return pNewNode;

}

/*在链表头插入数据节点*/

int addOneStudentToListHead(int num, char* name)

{

pStudentList pNewNode = NULL;

int result = 0;

if ((num < 0) || (name == NULL))

{

result = -1;

printf("error inoput parameter!\n");

return result;

}

pNewNode = createaOneStudentListNode();

pNewNode->num = num;

memcpy(pNewNode->name, name, strlen(name));

pNewNode->pNext = g_pstStudentList;

g_pstStudentList = pNewNode;

return result;

}

/*在链表尾部插入数据节点*/

int addOneStudentToListTail(int num, char* name)

{

pStudentList pTempHead = NULL;

pStudentList pTailNode = NULL;

pStudentList pNewNode = NULL;

int result = 0;

if ((num < 0) || (name == NULL))

{

result = -1;

printf("error input parameter!\n");

return result;

}

pTempHead = g_pstStudentList;

while(pTempHead)

{

if (pTempHead->pNext == NULL)

{

pTailNode = pTempHead;

}

pTempHead = pTempHead->pNext;

}

pNewNode = createaOneStudentListNode();

pNewNode->num = num;

memcpy(pNewNode->name, name, strlen(name));

pNewNode->pNext = NULL;

pTailNode->pNext = pNewNode;

return result;

}

/*输出整个链表中的学号信息，检查插入的是否正确，插入时没有考虑是否有相同学号*/

void printList()

{

pStudentList pTempHead = NULL;

pTempHead = g_pstStudentList;

while(pTempHead)

{

printf("studnet num = %d\n", pTempHead->num);

pTempHead = pTempHead->pNext;

}

}

/*释放整个链表的资源*/

void freeList()

{

pStudentList pTempHead = NULL;

pStudentList pFree = NULL;

int i = 0;

pTempHead = g_pstStudentList;

pFree = g_pstStudentList;

while(pTempHead)

{

pFree = pTempHead;

printf("free studnet num = %d\n", pTempHead->num);

pTempHead = pTempHead->pNext;

if (pFree != NULL)

{

printf("i = %d\n", i);/*测试是否正确释放资源*/

free(pFree);

}

++i;

}

}

int main()

{

/*构建头节点*/

char* cName = "allan";

g_pstStudentList = createaOneStudentListNode();

g_pstStudentList->num = 0;

memcpy(g_pstStudentList->name, cName, strlen(cName));

g_pstStudentList->pNext = NULL;

/*使用尾插法插入数据*/

char* cName1 = "allan1";

addOneStudentToListTail(1,cName1);

/*使用尾插法插入数据*/

char* cName2 = "allan2";

addOneStudentToListTail(2,cName2);

/*使用头插法插入数据*/

char* cName3 = "allan3";

addOneStudentToListHead(3,cName3);

/*输出当前链表中存储的学号，没有考虑学号的唯一性，假设输入的都是不同数字*/

printList();

/*使用完资源后进行释放资源，防止内存泄漏*/

freeList();

return 0;

}