指向 3D 数组 C++ 的指针 [英] pointers to 3D arrays C++

问题描述

C++:我在使用指向 3D 数组的指针时遇到问题 - 我正在编写一个带有 2D 数组的基本游戏，每个 2D 数组都是一个单独的级别，这些级别被分组到一个名为 map 的 3D 数组中.

C++: I have a problem with pointers to 3D arrays - I'm writing a basic game with 2D arrays, each 2D array is a separate level and these levels are grouped into a 3D array called map.

如何指向游戏的每个级别"?我的精简代码:

How can I point to each 'level' of my game? My streamlined code:

#include<iostream>
using namespace std;

#define LEVEL  2
#define HEIGHT 3
#define WIDTH  3

bool map[LEVEL][HEIGHT][WIDTH] = { {{1, 0, 1},   
                                    {1, 0, 1},   
                                    {0, 0, 1}},

                                   {{1, 1, 0},   
                                    {0, 0, 0},   
                                    {1, 0, 1}} };
int main()
{
  // ideally this points to level#1, then increments to level#2 
  bool *ptrMap;

  for(int i=0; i<HEIGHT; i++)
  {
     for(int j=0; j<WIDTH; j++)
       cout << map[1][i][j];       // [*ptrMap][i][j] ?
     cout << endl;
  }
return 0;    
}

推荐答案

Assign,

bool *ptrmap= &map[0][0][0];// gives you level 0
cout<<*ptrmap; //outputs the first element, level 0
cout<<*(ptrmap+9);// outputs first element, level 1

如果你不想指针线性递增，

If you do not want a linear increment of pointers,

i.e. map[0][0][0] as *ptrmap & map[1][0][0] as *(ptrmap + 9)

，我建议你使用指针的指针来创建矩阵(例如 bool ***ptrmap)，然后创建一个临时指针来取消引用它.

, I suggest you use pointer of pointers to create the matrix (ex. bool ***ptrmap) and then create a temporary pointer to dereference it.

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