链表（游标）

#include<stdio.h>#include<stdlib.h>#define SpaceSize 20typedef int PtrToNode;typedef PtrToNode List;typedef PtrToNode Position;typedef PtrToNode ElementType;struct Node{    ElementType Element;    Position Next;};struct Node CursorSpace[SpaceSize];void Init();List MakeEmpty(List L);int IsEmpty(const List L);int IsLast(const Position P,const List L);Position Find(ElementType x,const List L);void Delete(ElementType x,List L);void Insert(ElementType x,List L,Position P);void DeleteList(List);static Position CursorAlloc(){    Position P;    P=CursorSpace[0].Next;    CursorSpace[0].Next=CursorSpace[P].Next;    return P;}static void CursorFree(Position P){    CursorSpace[P].Next=CursorSpace[0].Next;    CursorSpace[0].Next=P;}void Init(){    int i;    for(i=0;i<SpaceSize;i++)CursorSpace[i].Next=i+1;    CursorSpace[i-1].Next=0;}int IsEmpty(List L){    return CursorSpace[L].Next==0;}int IsLast(Position P,List L){    return CursorSpace[P].Next==0;}Position Find(ElementType x,List L){    Position P;    P=CursorSpace[L].Next;    while(P && CursorSpace[P].Element!=x)    {P=CursorSpace[P].Next;printf("P=%d ",P);    }    return P;}/*int IsLast(const Position P,const List L){    Position q;    q=CursorSpace[L].Next;    while(q && q!=P)    {q=CursorSpace[q].Next;    }    return q;}*/void Delete(ElementType x,List L){    Position P,q,TmpCell;    P=CursorSpace[L].Next;    if(P && CursorSpace[P].Element!=x)    {q=CursorSpace[P].Next;while(q && CursorSpace[q].Element!=x){    P=q;    q=CursorSpace[q].Next;}    }    if(!IsLast(P,L))    {TmpCell=CursorSpace[P].Next;CursorSpace[P].Next=CursorSpace[TmpCell].Next;CursorFree(TmpCell);    }}void Insert(ElementType x,List L,Position P){    Position TmpCell;    TmpCell=CursorAlloc();    if(TmpCell==0)printf("out of space");    CursorSpace[TmpCell].Element=x;    CursorSpace[TmpCell].Next=CursorSpace[P].Next;    CursorSpace[P].Next=TmpCell;}void DeleteList(List L){    Position P,Tmp;    P=CursorSpace[L].Next;    CursorSpace[L].Next=0;    while(P)    {Tmp=CursorSpace[P].Next;CursorFree(P);P=Tmp;    }}void print(List L){    Position P;    P=CursorSpace[L].Next;    while(P)    {printf("%d  ",CursorSpace[P].Element);P=CursorSpace[P].Next;    }    printf("\n");}void main(){    Position P,L;    Init();    L=CursorAlloc();    printf("L=%d \n",L);    CursorSpace[L].Next=0;    P=L;    print(L);    int i;    for(i=0;i<9;i++)    {    Insert(i,L,P);//print(L);P=CursorSpace[P].Next;    }   print(L);   P=Find(5,L);   printf("Find(5,L)=%d \n",P);   P=Find(0,L);   printf("Find(0,L)=%d \n",P);   Delete(5,L);   print(L);}