Algorithmic Solutions > LEDA > LEDA Guide > Graphs and Related Data Types > Parameterized Graphs

## Parameterized Graphs

The data type GRAPH is a parameterized version of the data type `graph`. The nodes and edges of a Parameterized Graph contain additional (user defined) information.

Parameterized Graphs can represent directed and undirected graphs G=(V,E), where V is the list of nodes and E is the list of directed, respectively undirected, edges. Nodes and edges are of type item.

Simple example of how to use a parameterized graph

### Strengths

• all operations available for `graph` are also defined for Parameterized Graphs.
• additional operations to access and update information associated with nodes and edges conveniently
• can be used whereever `graph `is possible (assignments, arguments to functions with formal parameter `graph&`)
• flexible: Parameterized Graphs work well for dynamic graphs. It is possible to associate information with new nodes and edges without restriction. This is not possible for Node Arrays and Edge Arrays.
• faster than Node Arrays and Edge Arrays

• Only one piece of information can be associated with each node/edge of a graph

### Tips

• Use Parameterized Graphs if the information to associate with nodes and edges is an essential part of the graph.
• If you need to associate more than one piece of information with each node/edge of a graph, consider using one of the related data types.
• If you know the number of objects you want to associate with a node/edge beforehand, you can use the special constructor G(int n_slots,int e_slots) for graphs.

How to Associate Information with graphs

Node Arrays

Edge Arrays

Graph Algorithms

GraphWin for visualizing graphs and graph algorithms

Manual Entries:

LEDA Item Concept