# BFS

DSA

Binary Tree Zigzag Level Order Traversal

Binary Trees. Time O(n), Space O(n).

DSA Binary Tree LeetCode

DSA

Binary Tree Level Order Traversal

Binary Trees. Time O(n), Space O(n).

DSA Binary Tree LeetCode

DSA

Number of Ways to Arrive at Destination

Graphs. Time O(m log n), Space O(m+n).

DSA

Word Search

DFS - Backtracking approach. Optimal — Time O(mn * 4^L), Space O(1).

DSA

Word Ladder

Graphs problem — solution with code and analysis.

Hard·Aug 8, 2026

DSA

Valid Tree

Graphs problem — solution with code and analysis.

DSA

Surrounded Regions

Graphs. Time O(V^2).

DSA

Shortest Path in Binary Matrix

Graphs. Time O(V^2).

DSA

Rotten Oranges

Graphs. Time O(V^2).

DSA

Redundant Connection

Graphs. Time O(V+E).

DSA

Path with Minimum Effort

Graphs. Time O(ElogV).

DSA

Pacific Atlantic Water Flow

Covers: To Note, DFS, BFS. Optimal — Time O(m x n), Space O(m x n).

DSA

Number of Provinces

DFS vs BFS approach. Optimal — Time O(V^2), Space O(n).

DSA

Number of operations to make network connected

Covers: 1. DFS Based, Disjoint Set Based. Optimal — Time O(m * alpha(n), Space O(n).

DSA

Connected Components

Covers: DFS, Union Find. Optimal — Time O(V + E), Space O(V).

DSA

Flood Fill

Graphs. Time O(mxn), Space O(mxn).

Easy·Aug 8, 2026

DSA

Find the city with the smallest number of neighbors in a threshold distance

Covers: Dijkstra's Algo, Floyd warshall's. Optimal — Time O(n^3), Space O(n^2).

DSA

Find Eventual Safe States

Graphs. Space O(V).

DSA

Evaluate Division

Graphs. Time O(Q × (V + E), Space O(V).

DSA

Course Schedule - IV

Using DFS approach. Optimal — Time O(Q *(N+P), Space O(N+P).

DSA

Topological sort - BFS

Graphs. Time O(N), Space O(V+E).

DSA

Detect Cycle in an directed graph - BFS

Graphs. Time O(N), Space O(V+E).

DSA

Detect Cycle in an directed graph - DFS

Graphs. Time O(N), Space O(V+E).

DSA

Detect Cycle in an undirected graph - DFS

Graphs. Time O(N), Space O(V+E).

DSA

Detect Cycle in an undirected graph - BFS

Graphs. Time O(N), Space O(V+E).

DSA

BFS TRAVERSAL

Graphs. Time O(V+E), Space O(V+E).

DSA

DFS TRAVERSAL

Graphs. Time O(V+E), Space O(V+E).

DSA

Course Schedule - I

Covers: DFS, BFS - TOPOLOGICAL. Optimal — Time O(N+E), Space O(N).

DSA Graphs BFS 🏢 Amazon 🏢 Google

DSA

Clone Graph

Graphs problem — solution with code and analysis.

DSA

Alien Dictionary

Graphs problem — solution with code and analysis.

Hard·Aug 8, 2026

DSA Graphs BFS 🏢 Google

DSA

Minimum Spanning Tree: Prim's Algorithm

Graphs. Time O(ElogE), Space O(V^2).

DSA

Minimum Spanning Tree: Kruskal's Algorithm

Graphs. Time O(ElogE), Space O(V+E).

DSA

Shortest Path: Floyd Warshall Algorithm

Alogrithm approach. Optimal — Time O(V^3 ), Space O(V^2 ).

DSA

All Paths From Source to Target

Graphs. Time O(2^N * N), Space O(2^N * N).

DSA

Shortest Path Algorithm - Bellman Ford algorithm

5 approaches incl. Negative weight cycle:, Why (V-1) times?, Detection of a Negative Weig…, and more. Optimal — Time O(V*E), Space O(V).

DSA

Cheapest Flights Within K Stops

Graphs problem — solution with code and analysis.

DSA

Shortest Path Algorithm - Dijkstra algorithm

Covers: Data structures Used, If path is needed. Optimal — Time O( (E+V), Space O( |V| ).

DSA

Strongly Connected Components - Kosaraju's algorithm

The Algorithm approach. Optimal — Time O(V+E), Space O(V+E).

Hard·Aug 8, 2026

DSA

Bipartite Graph - DFS

Covers: Sample 1, Sample 2, Observations. Optimal — Time O(N*(V+E).

DSA

Bipartite Graph - BFS

Covers: Sample 1, Sample 2, Observations. Optimal — Time O(N*(V+E).

DSA

Course Schedule - II

Using BFS - Kahn's Algo approach. Optimal — Time O(N+P), Space O(N+P).

DSA Graphs BFS 🏢 Google

DSA

Number of Islands

Graphs. Time O(V^2).

DSA

Topological sort - DFS

Graphs. Time O(N), Space O(V+E).