MCQOPTIONS
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| 1. |
Let G = (V, E) be a directed, weighted graph with weight function w:E → ℝ.For some function f:v → ℝ, for each edge (u, v) ϵ E, define w’(u, v) as w(u, v) + f(u) – f(v).Which one of the options completes the following sentence so that it is TRUE?“The shortest paths in G under w are shortest paths under w’ too, ______”. |
| A. | for every f: v → ℝ |
| B. | if and only if ∀u ϵ V, f(u) is positive |
| C. | if and only if ∀u ϵ V, f(u) is negative |
| D. | if and only if f(u) is the distance from s to u in the graph obtained by adding a new vertex s to G and edges of zero weight from s to every vertex of G |
| Answer» B. if and only if ∀u ϵ V, f(u) is positive | |