Graphs

Traversal & coloring

BFS / DFS sweeps and 2-coloring.

• Is Graph Bipartite? (Medium)
• Number of Islands (Medium)

Ordering & cycles

Directed-graph dependency order and cycle detection.

• Topological sort (DFS post-order) (Medium)
• Course Schedule (Medium)

Weighted graphs

Shortest paths and minimum spanning trees over edge weights.

• Find Shortest Path with Dijkstra's (Medium)
• Union-Find · Kruskal MST (Medium)

Checkpoint

A graded check — pass to certify the Graphs topic.

Reference problems

27 imported reference solutions

• BFS Shortest Reach (Medium)
• Clone Graph (Medium)
• Find Shortest Path with BFS (Medium)
• Graph Traversal (Easy)
• Has Path from Source to Destination (Easy)
• Print All Paths from Source to Destination (Hard)
• Shortest Distance from All Buildings (Hard)
• Subset Component (Hard)
• Alien Dictionary (Hard)
• Remove Invalid Parentheses (Hard)
• Floyd City of Blinding Lights (Medium)
• Swim in Rising Water (Hard)
• Merging Communities (Medium)
• Similar String Groups (Hard)
• Word Ladder (Hard)
• Shortest Path in a Grid with Obstacles Elimination (Hard)
• Shortest Path in Binary Matrix (Medium)
• Robot Room Cleaner (Hard)
• The Earliest Moment When Everyone Become Friends (Medium)
• Find All Possible Recipes from Given Supplies (Medium)
• Detonate the Maximum Bombs (Medium)
• Maximal Network Rank (Medium)
• Number of Good Paths (Hard)
• Maximum Score of a Node Sequence (Hard)
• Find Degree of Vertex (Easy)
• Detect Cycle (Medium)
• Critical Connections in a Network (Hard)

Pattern Quest

Practice recognizing graphs problem shapes.