The cyclomatic complexity of a software module is calculated from a connected graph of the module (that shows the topology of control flow within the program):
Cyclomatic complexity (CC) = E - N + p
where E = the number of edges of the graph
N = the number of nodes of the graph
p = the number of connected components
To actually count these elements requires establishing a counting convention (tools to count cyclomatic complexity contain these conventions). The complexity number is generally considered to provide a stronger measure of a program's structural complexity than is provided by counting lines of code. Figure 6 is a connected graph of a simple program with a cyclomatic complexity of seven. Nodes are the numbered locations, which correspond to logic branch points; edges are the lines between the nodes.
