Bfs

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

Learn BFS shortest path in an unweighted graph: O(V+E) time, queue + parent[] for path reconstruction. Step-by-step for interviews—start now.

Compute shortest distances from a start node in an undirected graph with uniform edge weight using BFS.

Learn BFS traversal with a FIFO queue + visited set. Includes BFS pseudocode, example, and O(V+E) complexity—practice for FAANG interviews.

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

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

Learn graph cycle detection in an undirected graph using DFS/BFS parent tracking or Union-Find (DSU). O(V+E). Step-by-step—practice now.

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

Given an array where each element represents the maximum jump length, find the minimum number of jumps to reach the last index

Solve binary tree zig zag/spiral traversal with optimal BFS + deque. O(n) time, O(w) space. Step-by-step for interviews—practice now.

Traverse a binary tree level by level from left to right.

Find the maximum depth (height) of a binary tree

Count the number of islands in a 2D grid

Find the minimum time for all oranges to rot using BFS

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

Find a linear ordering of vertices in a directed acyclic graph

Traverse a binary tree vertically and return nodes by columns

Find the shortest transformation sequence from beginWord to endWord using single character changes