c - 如何在结构字符串数组中向下移动元素？

Question

这个问题已经有答案了:

Removing elements from an array in C (6 个回答)

已关闭 5 年前。

给定一个 struct 的数组对于多个元素，我想删除，例如元素 2，并希望元素 3,4,5.. 移动到 2,3,4。

在我下面的代码中，添加和删除功能工作正常。我尝试过 strcpy() 函数，但它不起作用。

    struct Books {
        char title[20];
        char author[20];
    };

void add_book(struct Books book1[], int *counter){

    fflush(stdin);
    printf("Title: ");
    gets(book1[*counter].title);
    printf("Author: ");
    gets(book1[*counter].author);
    *counter++;

    return;
}

void delete_book(struct Books book1[], int *counter){

    int i = 0;
    int delete = 0;
    printf("What nr of book you want to delete: ");
    scanf("%d", &delete);

    book1[delete-1].title[0] = '\0';
    book1[delete-1].author[0] = '\0';
    *counter--;

    /*
     here I want to move elements down one step if I delete for example one 
     element in the middle
    */
    return;
}

int main(){

    struct Books book1[50];
    int count = 0; //for keeping track of how many books in the register

    add_book(book1, &count);
    delete_book(book1, &count);

    return 0;
}

Answer 1

在您的评论表明您想要将剩余的书籍下移时，添加:

    memmove(&book1[delete-1],  &book1[delete], (*counter-delete)*sizeof(struct Books);
    *counter--;  // better to decrement it here

^(未测试)