Tree Recursive Insert
–node * insert(node * root, data & d){
– if (!root) {
– root = new node;
– root->d = d;
– root->left = NULL;
– root->right = NULL;
– }
– else if (root->d > d)
–   root->left = insert(root->left, d);
– else root->right=insert(root->right, d);
– return root;
–}
–