Alansh has to travel through a road having hills of different heights. Also each hill has a cave to pass through it, to avoid travelling extra distance of a hill. Alansh wants to travel through this road by taking at most K caves.

Given the roots of two binary trees root and rootSub, check if there is a subtree of root with the same structure and node values as rootSub.
A subtree of a tree T is a tree S consisting of a node in T and all of its descendants in T.

In an alien language, surprisingly, they also use English lowercase letters, but possibly in a different order. The order of the alphabet is some permutation of lowercase letters.

A Linked List is a data structure in which the objects are arranged in a linear order. Unlike Arrays, you cannot access any element directly through its index.

Given the root of a binary tree, return its maximum depth.
A binary tree’s maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.