Graphs
Problems on graph theory, including graph representation with adjacency matrices, incidence matrices and adjacency lists, vertex degrees, connectivity and connected components, cycles, bipartite graphs, shortest paths, minimum spanning trees, topological sorting, trees, flows, matchings and games on graphs.
Typical algorithms are breadth-first search, depth-first search, Dijkstra's algorithm, Floyd–Warshall, Bellman–Ford, Kruskal's and Prim's algorithms, and topological sort. The Graphs section of the library explains each of them.
Problems
Wolf Trails#1412
Medium
Bus Routes#1424
Hard
Students#1428
Very easy
Cycle#1455
Easy
Mine Field#1470
Easy
Constructing BST#1516
Very easy
Bracket Maze#1557
Medium
Blowing up the roads#1617
Very easy
Distance#1638
Easy
Gold Rush#1664
Hard
Graph condensation#1667
Very easy
Matching#1669
Very hard
The average distance#1670
Very easy
Lands of Antarctica#1685
Medium