Dfs

Given a sorted dictionary of alien language, find the order of characters in the alien alphabet

Find all possible paths from source node to target node in a directed acyclic graph (DAG)

Find all articulation points in an undirected graph - vertices whose removal increases the number of connected components

Traverse a binary tree in inorder (left -> root -> right)

Traverse a binary tree in preorder (root -> left -> right)

Traverse the boundary of a binary tree in anti-clockwise direction.

Create a deep copy of an undirected graph represented with adjacency lists

Count the number of nodes in a binary tree where the path from root to that node has no nodes with values greater than the current node.

Determine if you can finish all courses given prerequisite relationships using topological sorting

Implement depth-first search traversal for graphs

Determine if a directed graph contains a cycle

Determine if an undirected graph contains a cycle

Find the diameter (longest path) of a binary tree.

Find all bridges (critical edges) in an undirected graph using Tarjan's algorithm

Invert (mirror) a binary tree by swapping left and right children

Check if a graph can be colored with exactly two colors such that no two adjacent nodes have the same color

Find the lowest common ancestor of two nodes in a binary tree.

Find the maximum depth (height) of a binary tree

Find the maximum path sum in a binary tree.

Count the number of islands in a 2D grid

Check if there exists a root-to-leaf path with given sum.

Traverse binary tree in postorder (left, right, root)

Print all root-to-leaf paths in a binary tree

Serialize a binary tree to a string and deserialize it back to the original tree

Find all strongly connected components in a directed graph

Check if a binary tree is symmetric around its center.

Find a linear ordering of vertices in a directed acyclic graph

Traverse a binary tree vertically and return nodes by columns