#include<stdio.h>
#include<malloc.h>
#include<stdlib.h>
//定義鏈表節(jié)點(diǎn)
typedef struct Node
{
 int data;  //數(shù)據(jù)域
 struct Node * pNext; //指針域
}NODE, * PNODE;  //NODE等價(jià)于struct Node, PNODE等價(jià)于struct Node *
//函數(shù)聲明
PNODE createLinkList(void);    //創(chuàng)建鏈表的函數(shù)
void traverseLinkList(PNODE pHead);   //遍歷鏈表的函數(shù)
bool isEmpty(PNODE pHead);    //判斷鏈表是否為空的函數(shù)
int getLength(PNODE pHead);    //獲取鏈表長度的函數(shù)
bool insertElement(PNODE pHead, int pos, int val); //向鏈表中插入元素的函數(shù)，三個(gè)參數(shù)依次為鏈表頭結(jié)點(diǎn)、要插入元素的位置和要插入元素的值
bool deleteElement(PNODE pHead, int pos, int * pVal); //從鏈表中刪除元素的函數(shù)，三個(gè)參數(shù)依次為鏈表頭結(jié)點(diǎn)、要?jiǎng)h除的元素的位置和刪除的元素的值
void sort(PNODE pHead);     //對鏈表中的元素進(jìn)行排序的函數(shù)(基于冒泡排序)
int main(void)
{
 int val;   //用于保存刪除的元素
 PNODE pHead = NULL;  //PNODE等價(jià)于struct Node *
 pHead = createLinkList(); //創(chuàng)建一個(gè)非循環(huán)單鏈表，并將該鏈表的頭結(jié)點(diǎn)地址賦給pHead
 traverseLinkList(pHead); //調(diào)用遍歷鏈表的函數(shù)
 if(isEmpty(pHead))
 printf("鏈表為空！\n");
 else
 printf("鏈表不為空！\n");
 printf("鏈表的長度為：%d\n", getLength(pHead));
 //調(diào)用冒泡排序函數(shù)
 sort(pHead);
 //重新遍歷
 traverseLinkList(pHead);
 //向鏈表中指定位置處插入一個(gè)元素
 if(insertElement(pHead, 4, 30))
 printf("插入成功!插入的元素為：%d\n", 30);
 else
 printf("插入失敗!\n");
 //重新遍歷鏈表
 traverseLinkList(pHead);
 //刪除元素測試
 if(deleteElement(pHead, 3, &val))
 printf("元素刪除成功!刪除的元素是：%d\n", val);
 else
 printf("元素刪除失敗!\n");
 traverseLinkList(pHead);
 system("pause");
 return 0;
}

PNODE createLinkList(void)
{
 int length; //有效結(jié)點(diǎn)的長度
 int i;
 int value; //用來存放用戶輸入的結(jié)點(diǎn)的值
 //創(chuàng)建了一個(gè)不存放有效數(shù)據(jù)的頭結(jié)點(diǎn)
 PNODE pHead = (PNODE)malloc(sizeof(NODE));
 if(NULL == pHead)
 {
 printf("內(nèi)存分配失敗，程序退出！\n");
 exit(-1);
 }
 PNODE pTail = pHead; //pTail始終指向尾結(jié)點(diǎn)
 pTail->pNext = NULL; //清空指針域
 printf("請輸入您想要?jiǎng)?chuàng)建鏈表結(jié)點(diǎn)的個(gè)數(shù)：len = ");
 scanf("%d", &length);
 for(i=0;i<length;i++)
 {
 printf("請輸入第%d個(gè)結(jié)點(diǎn)的值：", i+1);
 scanf("%d", &value);
 PNODE pNew = (PNODE)malloc(sizeof(NODE));
 if(NULL == pHead)
 {
  printf("內(nèi)存分配失敗，程序退出！\n");
  exit(-1);
 }
 pNew->data = value; //向新結(jié)點(diǎn)中放入值
 pTail->pNext = pNew; //將尾結(jié)點(diǎn)指向新結(jié)點(diǎn)
 pNew->pNext = NULL; //將新結(jié)點(diǎn)的指針域清空
 pTail = pNew;  //將新結(jié)點(diǎn)賦給pTail,使pTail始終指向?yàn)槲步Y(jié)點(diǎn)
 }
 return pHead;
}

void traverseLinkList(PNODE pHead)
{
 PNODE p = pHead->pNext;
 while(NULL != p)
 {
 printf("%d ", p->data);
 p = p->pNext;
 }
 printf("\n");
 return;
}

bool isEmpty(PNODE pHead)
{
 if(NULL == pHead->pNext)
 return true;
 else
 return false;
}

int getLength(PNODE pHead)
{
 PNODE p = pHead->pNext;  //指向首節(jié)點(diǎn)
 int len = 0;   //記錄鏈表長度的變量
 while(NULL != p)
 {
 len++;
 p = p->pNext;  //p指向下一結(jié)點(diǎn)
 }
 return len;
}

void sort(PNODE pHead)
{
 int len = getLength(pHead); //獲取鏈表長度  
 int i, j, t;   //用于交換元素值的中間變量
 PNODE p, q;   //用于比較的兩個(gè)中間指針變量
 for(i=0,p=pHead->pNext ; i<len-1 ; i++,p=p->pNext)
 {
 for(j=i+1,q=p->pNext;j<len;j++,q=q->pNext)
 {
  if(p->data > q->data)
  {
  t = p->data;
  p->data = q->data;
  q->data = t;
  }
 }
 }
 return;
}

bool insertElement(PNODE pHead, int pos, int val)
{
 int i = 0;
 PNODE p = pHead;
 //判斷p是否為空并且使p最終指向pos位置的結(jié)點(diǎn)
 while(NULL!=p && i<pos-1)
 {
 p = p->pNext;
 i++;
 }
 if(NULL==p || i>pos-1)
 return false;
 //創(chuàng)建一個(gè)新結(jié)點(diǎn)
 PNODE pNew = (PNODE)malloc(sizeof(NODE));
 if(NULL == pNew)
 {
 printf("內(nèi)存分配失敗，程序退出!\n");
 exit(-1);
 }
 pNew->data = val;
 //定義一個(gè)臨時(shí)結(jié)點(diǎn)，指向當(dāng)前p的下一結(jié)點(diǎn)
 PNODE q = p->pNext;
 //將p指向新結(jié)點(diǎn)
 p->pNext = pNew;
 //將q指向之前p指向的結(jié)點(diǎn)
 pNew->pNext = q;
 return true;
}

bool deleteElement(PNODE pHead, int pos, int * pVal)
{
 int i = 0;
 PNODE p = pHead;
 //判斷p是否為空并且使p最終指向pos結(jié)點(diǎn)
 while(NULL!=p->pNext && i<pos-1)
 {
 p = p->pNext;
 i++;
 }
 if(NULL==p->pNext || i>pos-1)
 return false;
 //保存要?jiǎng)h除的結(jié)點(diǎn)
 * pVal = p->pNext->data;
 //刪除p后面的結(jié)點(diǎn)
 PNODE q = p->pNext;
 p->pNext = p->pNext->pNext;
 free(q);
 q = NULL;
 return true;
}