breadth first search

Same Tree

Check whether two binary trees are identical by comparing structure and node values using DFS or BFS traversal strategie…

Symmetric Tree

Determine if a binary tree is symmetric by comparing left and right subtrees using DFS or BFS traversal techniques effic…

Binary Tree Level Order Traversal

Perform a level order traversal on a binary tree using BFS to return node values level by level.

Binary Tree Zigzag Level Order Traversal

Traverse a binary tree in zigzag level order, alternating directions at each depth using BFS and state tracking techniqu…

Maximum Depth of Binary Tree

Find the maximum depth of a binary tree using traversal techniques to track the longest path from root to leaf.

Binary Tree Level Order Traversal II

Return a bottom-up level order traversal of a binary tree, processing nodes left to right while tracking each level accu…

Minimum Depth of Binary Tree

Find the minimum depth of a binary tree, which is the shortest path from the root node to the nearest leaf node.

Path Sum

Determine if a binary tree has a root-to-leaf path where the sum of node values equals a given target sum, using DFS or …

Populating Next Right Pointers in Each Node

Connect each node across every level by reusing established next links to traverse a perfect binary tree without extra q…

Populating Next Right Pointers in Each Node II

Populate each next pointer in a binary tree to its immediate right node, handling nulls and uneven levels efficiently us…

Word Ladder II

Find all shortest transformation sequences from beginWord to endWord using a dictionary, leveraging backtracking search …

Word Ladder

Find the shortest transformation sequence from a start word to an end word, with each word in the sequence differing by …

Surrounded Regions

Transform the matrix in-place by marking regions surrounded by 'X' as 'X', while keeping border-adjacent 'O's intact.

Clone Graph

Clone Graph involves cloning a graph using DFS, focusing on graph traversal and neighbor management using hash tables.

Binary Tree Right Side View

The Binary Tree Right Side View problem asks you to return the visible nodes from the right side of a binary tree, trave…

Number of Islands

Count the number of distinct islands in a binary grid using array traversal combined with depth-first search exploration…

Course Schedule

Determine if all courses can be completed by analyzing prerequisite dependencies using indegree tracking and topological…

Course Schedule II

Solve the 'Course Schedule II' problem using graph indegree and topological ordering, utilizing DFS or BFS to find the c…

Invert Binary Tree

Invert Binary Tree swaps every node's left and right children using tree traversal, with recursive DFS or iterative BFS …

Perfect Squares

Perfect Squares asks for the least number of perfect squares summing to a given integer n using dynamic programming or B…

Serialize and Deserialize Binary Tree

This problem asks to serialize and deserialize a binary tree, requiring an efficient approach to handle traversal and st…

Remove Invalid Parentheses

Remove the minimum number of invalid parentheses to generate all possible valid strings efficiently using backtracking a…

Minimum Height Trees

Identify all roots of a tree that produce minimum height using graph indegree analysis and topological trimming.

Coin Change

Find the minimum number of coins needed to reach a target amount using dynamic programming state transitions efficiently…