Graphs Recommended Order By Topic Basic Graph Traversals Order Question Difficulty Votes 1 Find If Path Exists in Graph Easy 2 Flood Fill Easy 3 All Paths From Source to Target Medium 4 Shortest Path in Binary Matrix Medium 5 Minesweeper Medium 6 Course Schedule II Medium 7 Rotting Oranges Medium 8 Word Ladder Hard Union Find Order Question Difficulty Votes 1 Number of Islands Medium 2 Max Area of Island Medium 3 Longest Consecutive Sequence Medium 4 Number of Connected Components in an Undirected Graph Medium