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.

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.

Mirror images mean right and left child of the two trees are interchanged. Thus, left child of first tree is right child of second tree. Traverse the Tree 1 and Tree 2 in Inorder fashion and store the node values of each Tree 1 & Tree 2 in two different arrays.

DFS (Depth-First Search) is an algorithm for traversing a graph. DFS starts from source vertex (graph) or root (in trees) and then visits an unvisited adjacent node v. After that it checks if node v has any adjacent node which is unvisited. If it reaches a leaf node or any node having no unvisited adjacent node. It backtracks and continue traversing other nodes.

BFS (Breadth-First Search) is one of the simplest algorithms for traversing a graph. Prim’s min-spanning-tree and Djikstra’s algorithm use similar ideas as BFS. BFS is also known as Level-order traversal because the algorithm discover all nodes at distance k from root before discovering any nodes at distance k+1.