线性表的操作

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

#define TRUE 1
#define FALSE 0
#define OK 1
#define ERROR 0
#define INIT_SIZE 10        //初始化表长
#define INCREMENT_SIZE 5    //分配增量

typedef int Status;
typedef int Elemtype;

/*
 * 存储结构
 */
typedef struct
{
    Elemtype *elem;    //存储空间基址
    int length;        //当前长度
    int size;        //当前分配的表长大小
}SqList;

/*
 * 初始化一个空的线性表
 */
Status InitList(SqList *L)
{
    L->elem = (Elemtype *) malloc(INIT_SIZE * sizeof(Elemtype));
    if (!L->elem)
    {
        return ERROR;
    }
    L->length = 0;
    L->size = INIT_SIZE;
    return OK;
}

/*
 * 销毁线性表
 */
Status DestroyList(SqList *L)
{
    free(L->elem);
    L->length = 0;
    L->size = 0;
    return OK;
}

/*
 * 清空线性表
 */
Status ClearList(SqList *L)
{
    L->length = 0;
    return OK;
}

/*
 * 判断线性表是否为空
 */
Status isEmpty(const SqList L)
{
    if (0 == L.length)
    {
        return TRUE;
    }
    else
    {
        return FALSE;
    }
}

/*
 * 获取长度
 */
Status getLength(const SqList L)
{
    return L.length;
}

/*
 * 根据位置获取元素
 */
Status GetElem(const SqList L, int i, Elemtype *e)
{
    if (i < 1 || i > L.length)
    {
        return ERROR;
    }
    *e = L.elem[i-1];
    return OK;
}

/*
 * 比较两个元素是否相等
 */
Status compare(Elemtype e1, Elemtype e2)
{
    if (e1 == e2)
    {
        return 0;
    }
    else if (e1 < e2)
    {
        return -1;
    }
    else
    {
        return 1;
    }
}

/*
 * 查找元素
 */
Status FindElem(const SqList L, Elemtype e, Status (*compare)(Elemtype, Elemtype))
{
    int i;
    for (i = 0; i < L.length; i++)
    {
        if (!(*compare)(L.elem[i], e))
        {
            return i + 1;
        }
    }
    if (i >= L.length)
    {
        return ERROR;
    }
}

/*
 * 查找前驱元素
 */
Status PreElem(const SqList L, Elemtype cur_e, Elemtype *pre_e)
{
    int i;
    for (i = 0; i < L.length; i++)
    {
        if (cur_e == L.elem[i])
        {
            if (i != 0)
            {
                *pre_e = L.elem[i - 1];
            }
            else
            {
                return ERROR;
            }
        }
    }
    if (i >= L.length)
    {
        return ERROR;
    }
}

/*
 * 查找后继元素
 */
Status NextElem(const SqList L, Elemtype cur_e, Elemtype *next_e)
{
    int i;
    for (i = 0; i < L.length; i++)
    {
        if (cur_e == L.elem[i])
        {
            if (i < L.length - 1)
            {
                *next_e = L.elem[i + 1];
                return OK;
            }
            else
            {
                return ERROR;
            }
        }
    }
    if (i >= L.length)
    {
        return ERROR;
    }
}

/*
 * 插入元素
 */
Status InsertElem(SqList *L, int i, Elemtype e)
{
    Elemtype *new;
    if (i < 1 || i > L->length + 1)
    {
        return ERROR;
    }
    if (L->length >= L->size)
    {
        new = (Elemtype*) realloc(L->elem, (L->size + INCREMENT_SIZE) * sizeof(Elemtype));
        if (!new)
        {
            return ERROR;
        }
        L->elem = new;
        L->size += INCREMENT_SIZE;
    }
    Elemtype *p = &L->elem[i - 1];
    Elemtype *q = &L->elem[L->length - 1];
    for (; q >= p; q--)
    {
        *(q + 1) = *q;
    }
    *p = e;
    ++L->length;
    return OK;
}

/*
 * 删除元素并返回其值
 */
Status DeleteElem(SqList *L, int i, Elemtype *e)
{
    if (i < 1 || i > L->length)
    {
        return ERROR;
    }
    Elemtype *p = &L->elem[i - 1];
    *e = *p;
    for (; p < &L->elem[L->length]; p++)
    {
        *(p) = *(p + 1);
    }
    --L->length;
    return OK;
}

/*
 * 访问元素
 */
void visit(Elemtype e)
{
    printf("%d ", e);
}

/*
 * 遍历线性表
 */
Status TraverseList(const SqList L, void (*visit)(Elemtype))
{
    int i;
    for(i = 0; i < L.length; i++)
    {
        visit(L.elem[i]);
    }
    return OK;
}

/*
 * 主函数测试
 */
int main()
{
    SqList L;
    if (InitList(&L))
    {
        Elemtype e;
        printf("init_success
");
        int i;
        for (i = 0; i < 10; i++)
        {
            InsertElem(&L, i + 1, i);
        }
        printf("length is %d
", getLength(L));
        if (GetElem(L, 1, &e)) {
            printf("The first element is %d
", e);
        }
        else
        {
            printf("element is not exist
");        
        }
        if (isEmpty(L))
        {
            printf("list is empty
");
        }
        else
        {
            printf("list is not empty
");
        }
        printf("The 5 at %d
", FindElem(L, 5, *compare));
        PreElem(L, 6, &e);
        printf("The 6's previous element is %d
", e);
        NextElem(L, 6, &e);
        printf("The 6's next element is %d
", e);
        DeleteElem(&L, 1, &e);
        printf("delete first element is %d
", e);
        printf("list:");
        TraverseList(L,visit);
        if (DestroyList(&L))
        {
            printf("
destroy_success
");
        }
    }
}