02-线性结构1 两个有序链表序列的合并 (15分)

#include <stdio.h>
#include <stdlib.h>

typedef int ElementType;
typedef struct Node *PtrToNode;
struct Node {
ElementType Data;
PtrToNode   Next;
};
typedef PtrToNode List;

List Read(); /* 细节在此不表 */
void Print( List L ); /* 细节在此不表；空链表将输出NULL */

List Merge( List L1, List L2 );

int main()
{
List L1, L2, L;
L1 = Read();
L2 = Read();
L = Merge(L1, L2);
Print(L);
Print(L1);
Print(L2);
return 0;
}

/* 你的代码将被嵌在这里 */

List Read()
{

List list = malloc(sizeof(PtrToNode));
list->Next = NULL;
List r = list;
int n = 0;
scanf("%d",&n);
while(n--)
{
List p = malloc(sizeof(PtrToNode));
scanf("%d",&p->Data);
p->Next = r->Next;
r->Next = p;
r = p;
}
return list;
}
void Print( List L )
{
//system("pause");
List p = L->Next;
if(!L->Next)
{
printf("NULL");
}
else
{
while(p)
{
printf("%d ",p->Data);
p = p->Next;
}
printf("\n");
}
}
List Merge( List L1, List L2 ){
List r;
//建立头结点而不能使用L1或L2的头结点是因为后边要将L1，L2置为NULL
PtrToNode L = ( PtrToNode )malloc( sizeof( struct Node ) );
List p=L1->Next;
List q=L2->Next;
r=L;
L->Next=NULL;
while(p!=NULL&&q!=NULL){
if(p->Data<q->Data){
r->Next=p;
p=p->Next;
r=r->Next;

}
else{
r->Next=q;
q=q->Next;
r=r->Next;
}

}
r->Next=NULL;
r->next = p?p:q;
L1->Next=NULL;
L2->Next=NULL;
return L;
}