两个有序链表序列的交集

已知两个非降序链表序列S1与S2，设计函数构造出S1与S2的交集新链表S3。

输入格式:

输入分两行，分别在每行给出由若干个正整数构成的非降序序列，用$-1$表示序列的结尾（$-1$不属于这个序列）。数字用空格间隔。

输出格式:

在一行中输出两个输入序列的交集序列，数字间用空格分开，结尾不能有多余空格；若新链表为空，输出NULL。

输入样例:

1 2 5 -12 4 5 8 10 -1

输出样例:

2 5

//其实没必要开辟新的空间来放Lc，可以继承La的内存，我这儿麻烦了#include <stdio.h>typedef struct LNode{    int data;    struct LNode *next;} LNode,*LinkList;void ListPrint_L(LinkList L){//输出单链表    LNode *p=L->next;  //p指向第一个元素结点    if(!p)        printf("NULL\n");    while(p!=NULL)    {        if(p->next!=NULL)            printf("%d ",p->data);        else            printf("%d\n",p->data);        p=p->next;    }}int main(){    LinkList La, Lb, Lc;    int da, flag;    flag = 0;   // LNode *curPtr, *rearPtr, *prePtr;    LNode *curPtr_a, *rearPtr_a, prePtr_a;    LNode *curPtr_b, *rearPtr_b, prePtr_b;    LNode *curPtr_c, *rearPtr_c, prePtr_c;    rearPtr_a = La = (LinkList)malloc(sizeof(LinkList));    rearPtr_b = Lb = (LinkList)malloc(sizeof(LinkList));    rearPtr_c = Lc = (LinkList)malloc(sizeof(LinkList));    scanf("%d", &da);    while(da != -1)    {        curPtr_a = (LNode *)malloc(sizeof(LNode));        curPtr_a->data = da;        rearPtr_a->next = curPtr_a;        rearPtr_a = curPtr_a;        scanf(" %d", &da);    }    rearPtr_a->next = NULL;    getchar();    scanf("%d", &da);    while(da != -1)    {        curPtr_b = (LNode *)malloc(sizeof(LNode));        curPtr_b->data = da;        rearPtr_b->next = curPtr_b;        rearPtr_b = curPtr_b;        scanf(" %d", &da);    }     rearPtr_b->next = NULL;     curPtr_a = La->next;     curPtr_b = Lb->next;     while(curPtr_a && curPtr_b)     {         if(curPtr_a->data == curPtr_b->data)         {            if(flag == 0)                printf("%d", curPtr_b->data);            else            {                printf(" %d", curPtr_b->data);            }            flag = 1;             curPtr_a = curPtr_a->next;             curPtr_b = curPtr_b->next;         }         else if(curPtr_a->data > curPtr_b->data){             curPtr_b = curPtr_b->next;         }         else         {             curPtr_a = curPtr_a->next;         }     }     if(flag == 0)        printf("NULL");//     rearPtr_c->next = NULL;//     ListPrint_L(Lc);}