UGC NET Computer Science Software Engineering Previous Year Questions (PYQs) – Page 9 of 11

In a sequence diagram, lifeline shows the existence or participation duration of an object during the interaction.

From the given figure, the increasing order of lifeline is from the object having the shortest lifeline to the object having the longest lifeline.

By observing the diagram:

Weather Data has the shortest lifeline.

Then comes Comms link.

Then comes Weather Station.

Sat Comms has the longest lifeline.

So, the increasing order is:

Weather Data $\rightarrow$ Comms link $\rightarrow$ Weather Station $\rightarrow$ Sat Comms

In the given flowgraph, some statements are combined into one node, like $(2,3)$ and $(4,5)$.

Nodes are:

$1,\ (2,3),\ (4,5),\ 6,\ 7,\ 8,\ 9,\ 10,\ 11$

Total number of nodes:

$9$

Cyclomatic complexity is:

$V(G)=E-N+2$

Here,

Number of nodes:

$N=9$

Number of edges:

$E=11$

So,

$V(G)=11-9+2$

$V(G)=4$

For a connected flowgraph:

Number of regions $=$ Cyclomatic complexity

From Q92,

Cyclomatic complexity $=4$

So, number of regions:

$4$

From the given flowgraph, one longest independent path can be written as:

$1\rightarrow(2,3)\rightarrow6\rightarrow7\rightarrow9\rightarrow10\rightarrow1\rightarrow11$

Now count the nodes in this path:

$1,\ (2,3),\ 6,\ 7,\ 9,\ 10,\ 1,\ 11$

Total nodes $=8$

Predicate nodes are those nodes from where more than one outgoing edge is present.

From the flowgraph:

Node $1$ has more than one outgoing path.

Node $(2,3)$ has two outgoing paths.

Node $6$ has two outgoing paths.

So, predicate nodes are:

$1,\ (2,3),\ 6$

Number of predicate nodes $=3$