I will list down some problems on the topic of trees and graphs that are commonly asked in interviews. Please revise topics on tress such as Binary Trees, Binary Search Tree (BST), Balancing a Tree, Full and Complete Trees, Binary Tree Traversals...
Trees and Graphs
Provide Depth First Search (DFS) Graph Algorithm.
Provide Breadth First Search (BFS) Graph Algorithm
Inorder Traversal Without Using Recursion
Preorder Traversal Without Using Recursion
Postorder Traversal Without Using Recursion With Two Stacks.
Postorder Traversal Without Using Recursion With One Stack
Check if a Binary Tree is a Binary Search Tree (BST) using Inorder Traversal.