Sum numbers formed from root to leaf

Signed-off-by: Vidhoon Viswanathan <vidhu2366@gmail.com>
Check if a given tree is a subtree of another

Signed-off-by: Vidhoon Viswanathan <vidhu2366@gmail.com>
Some more tree probs from GFG solved

Signed-off-by: Vidhoon Viswanathan <vidhu2366@gmail.com>