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
Cow at Large#10424
Very easy
Cave Paintings#10439
Very hard
Bandits in the Tree#10448
Very hard
Numerical Graph#10450
Medium
Server#10456
Easy
New Sky#10457
Very hard
Mail Lady#10493
Hard
Tug of war#10494
Medium
Push a Box#10519
Hard
Moocast (Silver)#10561
Medium