GraphLab is an interactive tool for learning graph theory and algorithms. Draw your own graph with vertices and edges, directed or undirected, weighted or not, and watch each algorithm run one step at a time. It runs in your browser with nothing to install, so it works for students, teachers and anyone preparing for a discrete mathematics or data structures exam.
Draw a tree and get its pre-order, in-order and post-order traversals, or go the other way: build a binary tree from pre-order + in-order or post-order + in-order sequences, or insert values one by one into a binary search tree (BST).
Step through bubble sort, selection sort, insertion sort, merge sort, quick sort, heap sort, counting sort and radix sort on your own numbers, plus topological sort of a directed graph.
Graph theory is the branch of mathematics that studies graphs: sets of vertices (nodes) joined by edges (links). Graphs model road maps, computer networks, social networks, task schedules and much more, and algorithms such as Dijkstra's, BFS, DFS and minimum spanning trees are how computers answer questions about them.