链表创建和链表遍历算法的演示

#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;

//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);
bool delete_list(PNODE,int,int *);
void sort_list(PNODE);
int main(void)
{
   PNODE pHead = NULL;
   pHead = create_list(); //创建一个非循环单链表，并将该链表的头结点的地址赋给pHead

   int len = length_list(pHead);
    printf("链表的长度为：%4d\n",len);
    printf("排序前链表序列为:\n");
    traverse_list(pHead);
     printf("排序后链表序列为:\n");
    sort_list(pHead);
    traverse_list(pHead);

    return 0;
}

PNODE create_list(void)
{
     int len; //用来存放有效结点的个数
     int i;
     int val; //用来临时存放用户输入的结点的值

     PNODE pHead = (PNODE)malloc(sizeof(NODE));
     if (NULL == pHead)
     {
         printf("分配失败，程序终止！");
         exit(-1);
     }
     PNODE pTail = pHead;
     pTail->pNext =NULL;
     printf("请输入您需要生成的链表结点的个数：len=");
     scanf("%d",&len);

     for (i=0;i<len;++i)
     {
         printf("请输入第%d个结点的值：",i+1);
         scanf("%d",&val);
         PNODE pNew = (PNODE)malloc(sizeof(NODE));
         if (NULL == pNew)
         {
             printf("分配失败，程序终止！");
             exit(-1);
         }
         pNew->data = val;
         pTail->pNext = pNew; //把pNew挂在了pTail的后边
         pNew->pNext = NULL;
     pTail = pNew;
     }
    return pHead;
}

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

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

int length_list(PNODE pHead)
{
     PNODE p = pHead->pNext;
     int len=0; //局部变量必须赋初值，否则排序会出错 因为len中为垃圾值

     while(NULL != p)
     {
         ++len;
         p = p->pNext;
     }
     return len;
}

void sort_list(PNODE pHead)
{
    int i,j,tmp;
    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)
           {
             tmp = p->data;
             p->data = q->data;
             q->data =tmp;
           }
        }

    }
}

/*
    for(i=0;i<len-1;++i)
    {
        for (j=i+1;j<len;++j)
        {
            if (a[i] > a[j])
            {
               tmp = a[i];
             a[i] = a[j];
             a[j] = tmp;
            }
        }
    }
*/