问题：类中含有指针，在对象的复制与赋值时存在问题，如何解决，多谢指点！
//实现矩阵的乘法
#include<iostream.h>
#include<math.h>
class matrix
{public:
friend istream& operator >>(istream&, matrix&);
friend ostream& operator <<(ostream&, matrix&);
friend matrix operator *(matrix&, matrix&);
private:
    int m,n;
int **array;
};
//矩阵的输入
istream& operator >>(istream& input, matrix& mx)
{cout <<"input the no. of rows:";
cin>>mx.m;
cout <<"input the no. of columns:";
cin>>mx.n;
cout<<"this matrix has "<<mx.m<<" rows "<<"and "<<mx.n<<" columns."<<endl;
cout<<"please input matrix elements according to rows:"<<endl;
if((mx.array=new int*[mx.m])==NULL)
cout<<"failure to creat room.";
for(int count=0;count < mx.m;count++)
mx.array[count]=new int[mx.n];
for(int r=0;r<mx.m;r++)
for(int c=0;c<mx.n;c++)
input>>mx.array[r][c];
return input;
}
//矩阵的输出
ostream& operator <<(ostream& output, matrix& mx)
{for(int r=0;r<mx.m;r++)
{cout<<endl;
for(int c=0;c<mx.n;c++)
output<<mx.array[r][c];
}
return output;
}
//矩阵相乘
matrix operator *(matrix& mx1, matrix& mx2)
{matrix temp;
temp.m=mx1.m;
temp.n=mx2.n;
if((temp.array=new int*[mx1.m])==NULL)
cout<<"failure to creat room.";
for(int count=0;count < mx1.m;count++)
temp.array[count]=new int[mx2.n];
if(mx1.n!=mx2.m)
cout<<"two matrixes cannot multiply!";
else
for(int i=0;i<mx1.m;i++)
for(int j=0;j<mx2.n;j++)
for(int t=0;t<mx1.n;t++)
temp.array[i][j]+=mx1.array[i][t]*mx2.array[t][j];
return temp;
}

int main()
{matrix mx1,mx2,mx3;
cin>>mx1>>mx2;
mx3=mx1*mx2;
cout<<"the rezult of two matrix multiply:";
cout<<mx3<<endl;
return 0;
}