I need some guidance related to medium-hard problems on Codechef.
Well you could learn some advanced data structures like Segment Tree, Fenwick Tree.Some advanced algorithms like Flow algorithms on a graph,Heavy Light Decomposition on a tree. As for solving DP hard-medium problems you require rigorous practice.(Still struggling there)
Hi, indiantarget, there is a very good article going on in discuss, it is currently active and is updated regularly, and you can follow the same.
thanks for such suggestions