Question

In binary search tree we have the node strucure as

class Node
{
    public:
    int key;
    Node *left;
    Node *right;

};  

So while creating a node we do

Node* createNode(int key)
{
    Node *node=new Node();
    node->key=key;
    node->left=NULL;
    node->right=NULL;

    return node;
}

Now i want key ad 2d matrix instead of integer key. Something like this

class Node
{
    public:
    char matrix[3][3];
    Node *left;
    Node *right;


};

How to create node now?

Node* createNode(char key[3][3])
{
    Node *node=new Node();
    node->matrix=key;     //This line
    return node;
}

Answer 1

In C++ it is equally simple:

vector<vector<double> > matrix;
vector<double> &row = matrix[i];

In C that would be

double *row = Matrix[i];

Note that the C way works in C++ as well, but you should prefer containers to plain pointers whenever you can.