Exercise 1: Connected Components With an Isolated Vertex — Possible Solution
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GIVEN
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Edges: P-Q, Q-R, S-T
Vertex U has no edges at all.

STEP 1: RUNNING THE REPEATED-TRAVERSAL METHOD
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Start from P (unvisited): traversal reaches Q (via P-Q), then R (via
Q-R). Component 1: {P, Q, R}.

Next unvisited vertex: S. Traversal reaches T (via S-T). No further
connections. Component 2: {S, T}.

Next unvisited vertex: U. U has no edges at all, so the traversal
starting from U immediately finds nothing further to explore.
Component 3: {U}.

RESULT
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Three connected components: {P, Q, R}, {S, T}, {U}

Per this chapter's own definition, an isolated vertex with no edges
at all is still a valid connected component - just one containing
only itself, since "connected to each other" trivially includes a
single vertex being connected to itself.

WHY THIS WORKS AS AN ANSWER
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The repeated-traversal method is applied exactly as this chapter's
own algorithm specifies - starting a new traversal from each still-
unvisited vertex - and the isolated vertex U is explicitly handled as
its own single-vertex component rather than overlooked.