单链表

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

typedef int ElementType;

struct SingleListNode
{
    ElementType Element;
    struct SingleListNode *Next;
};

struct SingleListNode* SingleListInit()
{
    struct SingleListNode* ListHead = malloc(sizeof(struct SingleListNode));
    ListHead -> Next = NULL;
    return ListHead;
}

int MakeSingleListEmpty(struct SingleListNode *ListHead)
{
    struct SingleListNode *Pointer_1;
    struct SingleListNode *Pointer_2;

    if(ListHead != NULL)
    {
        Pointer_1 = ListHead;
        Pointer_2 = ListHead -> Next;
        while(Pointer_2 != NULL)
        {
            Pointer_1 = Pointer_2;
            Pointer_2 = Pointer_2 -> Next;
            free(Pointer_1);
        }
        ListHead -> Next = NULL;
    }
    else
    {
        return 1;
    }
    return 0;
}

int SingleListIsEmpty(struct SingleListNode *ListHead)
{
    return (ListHead->Next == NULL);
}

int SingleListNodeIsLast(struct SingleListNode *PtrToNode,struct SingleListNode *ListHead)
{
    return (PtrToNode -> Next == NULL);
}

struct SingleListNode* SingleListNodeFind(ElementType ToBeFind,struct SingleListNode *ListHead)
{
    struct SingleListNode* Pointer;

    Pointer = ListHead -> Next;
    while(Pointer != NULL && Pointer -> Element != ToBeFind)
    {
        Pointer = Pointer -> Next;
    }

    return Pointer;
}

struct SingleListNode* SingleListNodeFindPrevious(ElementType ToBeFind,struct SingleListNode *ListHead)
{
    struct SingleListNode* Pointer;
    
    Pointer = ListHead;
    while(Pointer -> Next != NULL && Pointer -> Next -> Element != ToBeFind)
    {
        Pointer = Pointer -> Next;
    }
    
    return Pointer;
}

int SingleListNodeDelete(ElementType ToBeDelete,struct SingleListNode *ListHead)
{
    struct SingleListNode* Pointer;
    struct SingleListNode* TmpCell;

    Pointer = SingleListNodeFindPrevious(ToBeDelete,ListHead);

    if(!SingleListNodeIsLast(Pointer,ListHead))
    {
        TmpCell =  Pointer -> Next;
        Pointer -> Next = TmpCell -> Next;
        free(TmpCell);
        return 0;
    }
    return 1;
}

int SingleListNodeInsert(ElementType ToBeInsert,struct SingleListNode *ListHead,struct SingleListNode *PositionBeforeToBeInsert)
{
    struct SingleListNode *TmpCell;
    
    TmpCell = malloc(sizeof(struct SingleListNode));
    
    if(TmpCell == NULL)
    {
        return 1; 
    } 
    
    TmpCell -> Element = ToBeInsert;
    TmpCell -> Next = PositionBeforeToBeInsert -> Next;
    PositionBeforeToBeInsert -> Next = TmpCell;
    
    return 0;
}

int SingleListNodeAdd(ElementType ToBeInsert,struct SingleListNode *ListHead)
{
    struct SingleListNode *TmpCell;
    struct SingleListNode *LastNode;
    
    TmpCell = malloc(sizeof(struct SingleListNode));
    
    if(TmpCell == NULL)
    {
        return 1; 
    } 
    
    LastNode = ListHead;
    
    while(!SingleListNodeIsLast(LastNode,ListHead))
    {
        LastNode = LastNode -> Next;
    }
    
    TmpCell -> Element = ToBeInsert;
    TmpCell -> Next = LastNode -> Next;
    LastNode -> Next = TmpCell;
    
    return 0;
}

int SingleListDelete(struct SingleListNode *ListHead)
{
    struct SingleListNode *Pointer;
    
    if(ListHead == NULL)
    {
        return 1;
    } 
    while(ListHead != NULL)
    {
        Pointer = ListHead;
        ListHead = ListHead -> Next;
        free(Pointer);
    }
    return 0;
}
int main()
{
    struct SingleListNode *ListHead = SingleListInit();
    SingleListNodeAdd(1,ListHead);
    SingleListNodeAdd(2,ListHead);
    SingleListNodeInsert(3,ListHead,SingleListNodeFindPrevious(2,ListHead));
    SingleListNodeDelete(1,ListHead);
    SingleListNodeDelete(3,ListHead);
    printf("%d\n",ListHead->Next->Element);
    MakeSingleListEmpty(ListHead);
    //printf("%d\n",ListHead->Next->Element);
    SingleListDelete(ListHead);
    return 0;
}