# reachable

(definition)

**Definition:**
A *vertex* v is reachable from another vertex u if there is a *path* of any length from u to v.

**Also known as** reachability.

**See also**
*sink*, *source*, *connected graph*.

*Note:
Usually applied only to **directed graphs*, since any vertex in a *connected*, *undirected graph* is reachable from any other vertex.

Author: JM

## Implementation

Single-source and multiple-source reachability algorithms (Java) from Sedgewick and Wayne "Algorithms" 4th edition.

Go to the
Dictionary of Algorithms and Data
Structures home page.

If you have suggestions, corrections, or comments, please get in touch
with Paul Black.

Entry modified 15 October 2021.

HTML page formatted Fri Oct 15 16:48:46 2021.

Cite this as:

Jason McCabe, "reachable", in
*Dictionary of Algorithms and Data Structures* [online], Paul E. Black, ed. 15 October 2021. (accessed TODAY)
Available from: https://www.nist.gov/dads/HTML/reachable.html