Matrix

#pragma once

class Matrix3
{
private:
    int** mem;
    int size;
public:
    Matrix3(int _size = 0)
    {
        size = _size;
        mem = new int* [size];
        for (int i = 0; i < size; i++)
        {
            mem[i] = new int[size];
            for (int j = 0; j < size; j++)
            {
                mem[i][j] = 0;
            }
        }
    }
    ~Matrix3()
    {
        for (int i = 0; i < size; i++)
        {
            delete[]mem[i];
        }
        delete[]mem;
    }
    Matrix3(const Matrix3& tmp)
    {
        size = tmp.size;
        mem = new int* [size];
        for (int i = 0; i < size; i++)
        {
            mem[i] = tmp.mem[size];
            for (int j = 0; j < size; j++)
            {
                mem[i][j] = tmp.mem[i][j];
            }
        }
    }
    Matrix3& operator=(Matrix3 tmp)
    {
        if (size != tmp.size)
        {
            if (size != 0)
            {
                for (int i = 0; i < size; i++)
                {
                    delete[]mem[i];
                }
                delete[]mem;
            }
            size = tmp.size;
            mem = new int* [size];
        }
        for (int i = 0; i < size; i++)
        {
            mem[i] = new int[size];
            for (int j = 0; j < size; j++)
            {
                mem[i][j] = tmp.mem[i][j];
            }
        }
        return *this;
    }
};