13: Graph Data Structure

Graph
As you looked at the binary tree data structure, which provides a useful way of storing data for efficient searching, whereas each node can have up to two child nodes. More general tree structures can be created in which different numbers of child nodes are allowed for each node. All tree structures are hierarchical, which means that each node can only have one parent node, for example a family tree or a computer files system. But some data need to have connections between items which do not fit into a hierarchy like this. Graph data structures can be useful in these situations. A graph consists of a number of data items, each of which is called a vertex. Any vertex may be connected to any other, and these connections are called edges.
Some problems that can be represented by a graph:
- computer networks
- airline flights
- networks of paths in a city (roads map)
- telephone network or circuit network
- social networks like linkedIn, facebook
- course prerequisite structure
- tasks for completing a job
- flow of control through a program