In graph theory which one of these two will be called a weighted graph ?
- A graph where vertices have some weights or vales .
- A graph where edges have some weights or values .
- A graph where both edges and vertices have some weights or values
- A graph where neither edges nor vertices have any weights or values
I couldn't find a picture for the third case actually .
4 Answers
$\begingroup$There is some variation in the literature, but typically a weighted graph refers to an edge-weighted graph, that is a graph where edges have weights or values. Without the qualification of weighted, the graph is typically assumed to be unweighted.
$\endgroup$ $\begingroup$Answer choice (2) according to one popular text:
With each edge $e$ of $G$ let there be associated a real number $w(e)$, called its weight. Then $G$, together with these weights on its edges, is called a weighted graph.$^1$
[1] Bondy and Murty. Graph Theory with Applications. North-Holland, 1976 (page 15-16)
$\endgroup$ $\begingroup$Weighted graph is a graph in which real number is associated with each edge of graph..
$\endgroup$ $\begingroup$A weighted graph is also directed graph with weight on the edge of each graph
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