有序双链表的建立

/***把一个值插入到一个有序双链表，first是一个指向根节点的指针，**newValue是欲插入的新值。**返回值:如果欲插值原先已存在于链表中，函数返回0；**如果内存不足导致无法插入，函数返回-1；如果插入成功，函数返回1。*/#include <stdio.h>#include <stdlib.h>typedef struct NODE{    struct NODE *left;    struct NODE *right;    int value;    }Node;int dListInsert(Node **first,int newValue){    Node *current = *first;    Node *newNode,*pre = NULL;        while(current != NULL && current->value < newValue)    {        pre = current;        current = current->right;    }    if(current != NULL && current->value == newValue)        return 0;            newNode = (Node *)malloc(sizeof(Node));newNode->value = newValue;    if(newNode == NULL)        return -1;       newNode->right = current;                   //1    newNode->left = pre;                        //2    if(current != NULL)                                     //链表非空并且插入位置不在链表尾部        current->left = newNode;                //3        if(current == *first)                                   //新节点插入位置为链表首部或者链表本身为空        *first = newNode;        else         pre->right = newNode;                   //4            return 1;        }/***测试用,输入无序整数，通过调用dListinsert(),**建立有序且节点值不重复的双链表，然后打印之。*/int main(void){    Node *head = NULL;    Node *temp;    int count,value;        count = 8;                             //测试整数的个数    printf("请输入%d个整数:\n",count);    while(count--)    {        scanf("%d",&value);dListInsert(&head,value);    }        temp = head;    while(temp)    {        printf("%d ",temp->value);        temp = temp->right;    }    printf("\n");        return 0;}