CountKeyK1K2.cpp

//In A Binary tree how many keys are >= k1  && <= k2

int KeyCount(Node* root,int k1, int k2)
{
   if(root == NULL) return 0;

   if(root.key < k1) return KeyCount(root->right,k1,k2);

   if(root.key > k2) return KeyCount(root->left,k1,k2);

  return 1 + KeyCount(root->left,k1,k2) + KeyCount(root->right,k1,k2);
}