顺序表的实现

#include <stdio.h>
#include <stdlib.h>
#define MaxSize 100
/*


    struct SqList sq;
    struct SqList* p_sq = &sq;
    p_sq->length = 0;

    struct SqList sq;
    struct SqList* p_sq = &sq;
    p_sq = malloc(sizeof(struct SqList));
    p_sq->length = 0;


第一段代码 p_sq 指向 sq，因此 p_sq->length 就是 sq.length；
第二段代码 p_sq 指向一个新分配的内存，p_sq->length 不是 sq.length，sq.length 没有被初始化或赋值。

*/
typedef int Elemtype;
typedef struct SqList
{
    Elemtype data[MaxSize];
    int length; //顺序表的长度
};
void Init__List(struct SqList *sq);//初始化顺序表
int Length__List(struct SqList sq);//求顺序表的长度
Elemtype Get__List(struct SqList sq, int index);//获取第index个元素,index>0
int Locate__List(struct SqList sq, int value);//获取值为value的下标,下标>0
void Insert__List(struct SqList *sq, int index, int value);//插入第index位置，值为value,index>0
void Delete__List(struct SqList *sq, int index);//删除第index个位置的值，index>0
void ShowSqList(struct SqList sq);//展示顺序表
int main(void)
{

    struct SqList sq;
    Init__List(&sq);
    printf("线性表的长度是%d\n", sq.length);
    for (int i = 1; i <= 101; i++)
    {
        Insert__List(&sq, i, i * 1000);
    }
    ShowSqList(sq);
    // printf("-------------------------\n");
    // Delete__List(&sq,1);
    // ShowSqList(sq);
    // printf("-------------------------\n");
    // Delete__List(&sq,10);
    // ShowSqList(sq);

    // printf("顺序表的长度是:%d\n",Length__List(sq));
    // printf("-------------------------\n");
    // for(int i=0;i<sq.length;i++){
    //     printf("第%d个元素是%d\n",i+1,sq.data[i]);
    // }
    system("pause");
    return 0;
}

void Init__List(struct SqList *sq)
{
    //sq = (struct SqList *)malloc(sizeof(struct SqList));
    sq->length = 0;
}

//求顺序表的长度
int Length__List(struct SqList sq)
{

    return sq.length;
}
/*
返回线性表L中的第i个元素的值或地址
*/
Elemtype Get__List(struct SqList sq, int index)
{
    if (index <= 0 || index > sq.length)
    {
        return -1; //-1表示不存在
    }

    return sq.data[index - 1];
}

int Locate__List(struct SqList sq, int value)
{
    for (int i = 1; i <= sq.length; i++)
    {
        if (sq.data[i - 1] == value)
        {
            return i - 1;
        }
    }

    return -1;
}
void Insert__List(struct SqList *sq, int index, int value)
{
    if (index <= 0 || index > sq->length + 1)
    {
        printf("插入的位置错误\n");
        return;
    }

    if (sq->length == MaxSize)
    {
        printf("空间已满\n");
        return;
    }
    for (int i = sq->length - 1; i >= index - 1; i--)
    {
        sq->data[i + 1] = sq->data[i];
    }
    sq->data[index - 1] = value;
    sq->length++;
}

void Delete__List(struct SqList *sq, int index)
{
    if (index <= 0 || index > sq->length)
    {
        printf("删除的位置错误\n");
        return;
    }

    for (int i = index - 1; i < sq->length; i++)
    {
        sq->data[i] = sq->data[i + 1];
    }

    sq->length--;
}

void ShowSqList(struct SqList sq)
{
    for (int i = 0; i < sq.length; i++)
    {
        printf("%d\n", sq.data[i]);
    }
}