动态分配存储的顺序表

/*

 * 动态分配存储的顺序表

 */



#include <stdio.h>

#include <stdlib.h>



#define INIT_SIZE 100

#define EXPAND_SIZE 50



typedef int ElemType;

typedef struct {

    ElemType *head;

    int len; // 顺序表当前元素个数

    int size; // 顺序表当前最大容量

} Sqlist;



int init_sqlist(Sqlist *list)

{

    if( (list->head = malloc(INIT_SIZE*sizeof(ElemType))) == NULL ) // 分配初始空间

    {

        printf("init error.\n");

        return -1;

    }

    list->len = 0;

    list->size = INIT_SIZE;

    return 0;

}



int insert_sqlist(Sqlist *list, int n, ElemType item)

{

    ElemType *t;

    if( n > list->len+1 || n < 1 ) // 插入位置非法

    {

        printf("insert error, location illegal.\n");

        return -1;

    }

    if( list->len == list->size ) // 顺序表当前容量已经全部用完, 扩容

    {

        t = realloc( list->head, (list->size + EXPAND_SIZE)*sizeof(ElemType) );

        if( t == NULL)

        {

            printf("realloc error.\n");

            return -1;

        }

        list->head = t;

        list->size += EXPAND_SIZE;

    }



    for( t = list->head + list->len ; t > (list->head + (n-1)) ; t-- ) // 原第n位置元素及其后的元素依次后移

        *t = *(t-1);

    *t = item;

    list->len ++;

    return 0;

}



int delete_sqlist(Sqlist *list, int n)

{

    ElemType *t;

    if( n > list->len || n < 1 ) // 删除位置非法

    {

        printf("delete error, location illegal.\n");

        return -1;

    }



    for( t= list->head + (n-1) ; t < list->head + (list->len-1) ; t++ ) // 第n+1位置元素及其后的元素依次前移

        *t = *(t+1);

    list->len --;

    return 0;

}



int free_sqlist(Sqlist *list)

{

    free(list->head);

    return 0;

}



void print_sqlist(Sqlist list)

{

    int i;

    for(i=0; i<list.len; i++)

        printf("%d ", list.head[i]);

    printf("\n");

}



int main(void)

{

    Sqlist list;

    init_sqlist(&list);



    int i;

    for( i=1 ; i<=117; i++)

        insert_sqlist(&list,i,i);

    print_sqlist(list);



    delete_sqlist(&list, 5);

    delete_sqlist(&list, 115);

    print_sqlist(list);



    free_sqlist(&list);

    return 0;

}