创建三维指针 [英] Create a d-dimensional pointer

问题描述

我们用来用符号*表示一个指针.重复该过程，我们获得一个双"指针**，一个三重"指针***，更一般地，一个"d维"指针(对于每个d个正自然数).

We use to indicate a pointer with the symbol *. Iterating the procedure, we obtain a "double" pointer **, a "triple" pointer *** and, more generally, a "d-dimensional" pointer (for each d positive natural number).

问题:给定这样的d作为输入，将S定义为d维指针.

Problem: given such a d as an input, define S to be a d-dimensional pointer.

由于我是几天前才开始研究动态结构的，因此我对此问题有点麻烦. 有人有建议/提示吗?

Because I started studying dynamic structures only some days ago, I am unfortunately a bit in trouble with this problem. Does anyone have a suggestion/hint?

预先感谢您，对于可能太基本的问题，我深表歉意.

Thank you in advance, and my apologies for my probably too basic question.

Ps:为了简洁起见，我使用了指针"一词，但未指定其类型.

Ps: I used the word "pointer" without specify its type only for sake of brevity.

推荐答案

只要满足两个条件，此问题就可以在C中解决:

This problem has a solution in C as long as two conditions are met:

• d的值在编译时已知，并且
• d具有预定义的限制，例如10

• The value of d is known at compile time, and
• d has a pre-defined limit, e.g. 10

您可以通过定义一系列宏并粘贴" d的值作为标记来解决此问题:

You can solve this problem by defining a series of macros and "pasting" the value of d as a token:

#define D_PTR(d,T) D_PTR##d(T)
#define D_PTR0(T) T
#define D_PTR1(T) T*
#define D_PTR2(T) T**
#define D_PTR3(T) T***
...
#define D_PTR10(T) T**********

现在您可以像这样声明d维指针:

Now you can declare d-dimension pointers like this:

D_PTR(5,int) ptr5 = NULL;

演示.

这篇关于创建三维指针的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！