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<<"\tsizeof(char) = "<<sizeof( char )

<<"\nsizeof s = "<<sizeof(s)

<<"\tsizeof(short) = "<<sizeof( short )

<<"\nsizeof i = "<<sizeof (i)

<<"\tsizeof(int) = "<<sizeof( int )

<<"\nsizeof l = "<<sizeof(l)

<<"\tsizeof(long) = "<<sizeof( long )

<<"\nsizeof f = "<<sizeof (f)

<<"\tsizeof(float) = "<<sizeof(float)

<<"\nsizeof d = "<<sizeof (d)

<<"\tsizeof(double) = "<<sizeof(double)


return 0;


The output of the above program:

sizeof c = 1sizeof(char) = 1

sizeof s = 2sizeof(short) = 2

sizeof i = 4sizeof(int) = 4

sizeof l = 4sizeof(long) = 4

sizeof f = 4sizeof(float) = 4

sizeof d = 8sizeof(double) = 8

Focus on problem solving

In this section, the software development procedure presented in the previous chapter is applied to a specific programming problem. This procedure can be applied to any programming problem to produce a completed program and forms the foundation for all programs developed in this text.

Problem: Telephone Switching Networks

A directly connected telephone network is one in which all telephones in the network are connected directly and do not require a central switching station to establish calls between two telephones.

The number of direct lines needed to maintain a directly connected network for n telephones is given by the formula:

lines = n(n-1)/2

For example, directly connecting four telephones requires six individual lines.

Using the formula, write a C++ program that determines the number of direct lines for 100 telephones and the additional lines required if 10 new telephones were added to the network. Use our top-down software development procedure.

Step 1: analyze the problem

For this program, two outputs are required: the number of direct lines required for 100 telephones and the additional lines needed when 10 new telephones are added to the existing network. The input item required for this problem is the number of telephones, which is denoted as n in the formula.

Step 2: develop a solution

The first output is easily obtained using the given formula lines = n(n-1)/2. Although there is no formula given for additional lines, we can use the given formula to determine the total number of lines needed for 110 subscribers. Subtracting the number of lines for 100 subscribers from the number of lines needed for 110 subscribers then yields the number of additional lines required. Thus, the complete algorithm for our program, in pseudocode, is:

Calculate the number of direct lines for 100 subscribers.

Calculate the number of direct lines for 110 subscribers.

Calculate the additional lined needed, which is the

difference between the second and the first calculation.

Display the number of lines for 100 subscribers.

Display the additional lines needed.

Step 3: code the solution

The following program provides the necessary code.


int main()


int numin1, numin2, lines1, lines2;

numin1 = 100;

numin2 = 110;

lines1 = numin1*(numin1 – 1)/2;

lines2 = numin2*(numin2 – 1)/2;

cout<<“The number of initial lines is “<<lines1<<“.\n”;

cout<<“There are “<<lines2 – lines1

<<“ additional lines needed.\n”;

return 0;


Step 4: test and correct the program

The following output is produced when the program is compiled and executed:

The number of initial lines is 4950.

There are 1045 additional lines needed.

Because the displayed value agrees with the hand calculation, we have established a degree of confidence in the program.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Programming fundamentals in c++. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10788/1.1
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