链表

#include<stdio.h>#include<malloc.h>#include<stdlib.h>typedef struct Node{  int data;//数据域;  struct Node * pNext; //指针域;}NODE, *PNODE; //NODE等价于 struct Node, PNODE 等价于 struct Node * ; //函数声明 PNODE create_list(void); void traverse_list(PNODE pHead); bool is_empty(PNODE pHead); int length_list(PNODE); bool insert_list(PNODE, int, int);//在pHead所指向链表的第pos个节点的前面插入一个新的节点，该节点的值是val,并且pos的值是从1开始;  bool delete_list(PNODE, int, int *); void sort_list(PNODE);   //delete_list(pHead, 3, &val);int main(void){PNODE pHead = NULL; //等价于 struct Node * pHead = NULL;int val;pHead = create_list(); //create_list()功能:创建一个非循环单链表，并将该链表的头结点的地址付给pHead; traverse_list(pHead);//insert_list(pHead, 4, 33);if ( delete_list(pHead, 4, &val) ){printf("删除成功，您删除的元素是：%d\n", val);}else {printf("删除失败!您删除的元素不存在\n");}traverse_list(pHead);//int len = length_list(pHead);//printf("链表的长度是%d\n", len);//sort_list(pHead);//traverse_list(pHead);/*if ( is_empty(pHead) )     printf("链表为空!\n");else printf("链表不空!\n");     */return 0;}PNODE create_list(void){int len; //用来存放有效节点的个数 int i;int val; //用来临时存放用户输入的节点的值 ;//分配了一个不存放有效数据的头结点 PNODE pHead = (PNODE)malloc(sizeof(Node)); //PNODE pHead 为头指针 if (NULL == pHead){printf("分配失败，程序终止！\n");exit(-1);}PNODE pTail = pHead;pTail->pNext = NULL;printf("请输入您需要生成的链表节点的个数：len = ");scanf("%d", &len);for(i=0;i<len; ++i){printf("请输入第%d个节点的值：", i+1); //因为i从0开始，所以写i+1; scanf("%d", &val);  PNODE pNew = (PNODE)malloc(sizeof(Node)); if (NULL == pNew)  {printf("分配失败，程序终止！\n");exit(-1);  }  pNew->data = val;//  pHead->pNext = pNew;//  pNew->pNext = NULL; //最后一个节点的指针域为空 ;  pTail->pNext = pNew;  pNew->pNext = NULL;  pTail = pNew; //pTail就永远是尾节点了;}return pHead;}void traverse_list(PNODE pHead){PNODE p = pHead->pNext;while (p != NULL){printf("%d ",p->data);p = p->pNext;}printf("\n");return ;} bool is_empty(PNODE pHead) { if (pHead->pNext == NULL) return true; else return false;  }  int length_list(PNODE pHead) { PNODE p = pHead->pNext; int len = 0;  while (p != NULL) { ++len; p = p->pNext; } return len; }  void sort_list(PNODE pHead) { int i, j, t;  int len = length_list(pHead); PNODE p, q;  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) //类似于数组中的：a[i] > a[j]; { t = p->data;//类似于数组中的：t = a[i]; p->data = q->data;//类似于数组中的：a[i] = a[j]; q->data = t;//类似于数组中的：a[j] = t; } } } return ; }  //在pHead所指向链表的第pos个节点的前面插入一个新的节点，该节点的值是val,并且pos的值是从1开始;  bool insert_list(PNODE pHead, int pos, int val) { int i = 0; PNODE p = pHead;  while(p != NULL && i<pos-1) { p = p->pNext; ++i;  }     if(i>pos-1 || p==NULL)  return false;    PNODE pNew = (PNODE)malloc(sizeof(NODE));  if(pNew == NULL)  {  printf("动态分配内存失败!\n");  exit(-1);  }  pNew->data = val;  PNODE q = p->pNext;  p->pNext = pNew;  pNew->pNext =q;    return true;  }  bool delete_list(PNODE pHead, int pos, int *pVal) { int i = 0; PNODE p = pHead;  while(NULL != p->pNext && i<pos-1) { p = p->pNext; ++i;  }     if(i>pos-1 || NULL==p->pNext)  return false;    PNODE q = p->pNext;  *pVal = q->data;    //删除p节点后面的结点   p->pNext = p->pNext->pNext;  free(q);  q = NULL;    return true;  }