036 很难蒙混过关的CArray3d三维数组模板类

#include <iostream>
#include <iomanip> 
#include <cstring>
using namespace std;
template <class T>
class CArray3D
{
    // 在此处补充你的代码
public:

    int x, y, z;
    T * arr;
    CArray3D(int _x,int _y,int _z):x(_x),y(_y),z(_z){
        arr = new T[x*y*z];
    }
    
    class B {
    public:
        T* p;
        int z;
        B(T* p_, int z_) :p(p_), z(z_) {}
        T* operator[](int index) {
            return  p + z * index;
        }
        operator T* () {
            return p;
        }

    };

    B operator[](int indx) {
        T* p = arr + indx * z * y;
        return B(p,z);
    }


};

CArray3D<int> a(3, 4, 5);
CArray3D<double> b(3, 2, 2);
void PrintA()
{
    for (int i = 0;i < 3; ++i) {
        cout << "layer " << i << ":" << endl;
        for (int j = 0; j < 4; ++j) {
            for (int k = 0; k < 5; ++k)
                cout << a[i][j][k] << ",";
            cout << endl;
        }
    }
}
void PrintB()
{
    for (int i = 0;i < 3; ++i) {
        cout << "layer " << i << ":" << endl;
        for (int j = 0; j < 2; ++j) {
            for (int k = 0; k < 2; ++k)
                cout << b[i][j][k] << ",";
            cout << endl;
        }
    }
}

int main()
{

    int No = 0;
    for (int i = 0; i < 3; ++i) {
        a[i];
        for (int j = 0; j < 4; ++j) {
            a[j][i];
            for (int k = 0; k < 5; ++k)
                a[i][j][k] = No++;
            a[j][i][i];
        }
    }
    PrintA();
    memset(a[1], -1, 20 * sizeof(int));
    memset(a[1], -1, 20 * sizeof(int));
    PrintA();
    memset(a[1][1], 0, 5 * sizeof(int));
    PrintA();

    for (int i = 0; i < 3; ++i)
        for (int j = 0; j < 2; ++j)
            for (int k = 0; k < 2; ++k)
                b[i][j][k] = 10.0 / (i + j + k + 1);
    PrintB();
    int n = a[0][1][2];
    double f = b[0][1][1];
    cout << "****" << endl;
    cout << n << "," << f << endl;

    return 0;
}