Lab 2

Prepared by:
DR. Mennatallah Hesham Ibrahim
Presented by: Haidy Hamed
Department of Computer Science
Assignment
 Draw a flowchart and write a program that
calculate Kelvin and Fahrenheit from a Celsius
degree entered by the user.
k = c + 273
f = c * 5/9 + 32
Program Code
#include <cstdlib>
#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
float c,k,f;
cout << "Please Enter a Celsius Degree: ";
cin >> c;
k = c + 273;
f = c * 5/9 + 32;
cout << "Kelven: " << k << '\n';
cout << "Fehrenhit: " << f << '\n';
system("PAUSE");
return EXIT_SUCCESS;
}
Exercise 1
 Write a C++ program that accepts an employee salary and a
tax percentage then computes the monthly net salary (ns)
and determine his income level according to the following
table:
Code
#include <cstdlib>
#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
int basic_salary,tax_percent,net_salary,tax_value;
cout << "Please enter your net basic salary: ";
cin >> basic_salary;
cout << "Please enter your tax percentage: ";
cin >> tax_percent;
tax_value=basic_salary*tax_percent/100;
net_salary=basic_salary-tax_value;
cout << "Your net salary: " << net_salary<<endl;
Code
if(net_salary<3000)
cout << "Low"<<endl;
else if(net_salary<8000)
cout << "Moderate"<<endl;
else
cout << "Excellent"<<endl;
system("PAUSE");
return EXIT_SUCCESS;
}
The Switch Statement
 Is called multiple selection structure
 Selects the action to be performed from many different
actions
 It is not necessary to enclose a multi-statement case in
braces
The Switch Statement
Advanced Calculator
 Write a program that simulate a simple calculator that
accepts two operands (use floating point) and the desired
operation (+, - , %, * , /) then displays the result. It prevents
division by 0. When it finishes the calculation the program
should ask the user whether he wants to do another
calculation or not
Code
#include <cstdlib>
#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
double num1,num2,result;
char Op;
cout << "Enter the first number : ";
cin >> num1;
cout << "Enter your operation : ";
cin >> Op;
cout << "Enter the second number : ";
cin >> num2;
Code (Cont.)
switch (Op)
{
case '+' :
result=num1+num2;
break;
case '-' :
result=num1-num2;
break;
case '*' :
result=num1*num2;
break;
case '%' :
result=(int)num1%(int)num2;
break;
Code (Cont.)
case '/' :
if (num2 == 0)
cout << "You cannot divide by zero";
else
result=num1/num2;
break;
default :
cout << "Sorry your operation is wrong "<<endl;
}
cout << "Result= " << result;
system("PAUSE");
return EXIT_SUCCESS;
}
Exercise 2: Rewrite the following code using
nested if/else. What does it print out?
int x=7;
int y=3;
char op='%';
switch(op)
{
case '-':
cout <<x-y;
break;
case ‘+':
cout <<x+y;
break;
case '*':
cout <<x*y;
break;
}
Answer
int x=7;
int y=3;
char op='%';
if(op=='-')
cout <<x-y;
else if(op==‘+')
cout <<x+y;
else
cout <<x*y;
Repeated Processing
1. for Loop
2. while Loop
3. do … while Loop
Loops
 A control structure that cause a statement or a
group of statements to repeat
for Loop
while Loop
 Has 2 parts:
1. Condition that is tested for a true or false value
2. A statement or block that is repeated as long as the expression
is true (loop body)
 Format
while(expression)
{
Statement;
Statement;
}
 Pretest loop
do … while Loop
 Has 2 parts:
1. Condition that is tested for a true or false value
2. A statement or block that is repeated as long as the expression
is true (loop body)
 Format
do
{
Statement;
Statement;
} while(expression);
 Postest loop
 Guaranteed to loop at least one time
Program 1
 Write a program that calculate the following
S= 1+4+7+10+….n
Code
#include <cstdlib>
#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
int sum=0,n;
cout << "Please Enter value for n: ";
cin>>n;
for(int x=1;x<=n;x+=3)
{
sum+=x;
}
cout << "Sum = " << sum << '\n';
system("PAUSE");
return EXIT_SUCCESS;
}
Program 2
 Writ a program that accepts a number and display it’s
factorial (factorial(x)=x*(x-1)*(x-2)*(x-3)….*3*2*1)
Code
#include <cstdlib>
#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
int x,fact=1;
cout <<"Enter a number: "<<endl;
cin>>x;
if(x==0)
cout<< "Factorial of 0 is " << fact <<endl;
else if(x<0)
cout<< " No Factorial "<<endl;
else
{
for(int i=x;i>=1;i--)
fact=fact*i;
}
cout <<"Factorial of "<<x<<" is "<<fact<<endl;
system("PAUSE");
return EXIT_SUCCESS;
}
Program 3
 Write a program that reads a number between 1 and 10 from
the user and print “small” if the number is 1,2 or 3 ,print
“medium” if the number is 4,5 or 6, otherwise print large.
Code
#include <cstdlib>
#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
int x;
do
{
cout << "Please enter a number";
cin >> x;
}while (x>10 || x<1);
if(x <= 3)
cout << "small" << endl;
else if(x<=6)
cout << "medium" << endl;
else
cout << "large" << endl;
system("PAUSE");
return EXIT_SUCCESS;
}
My Contact
 Haidy.hamed.mustafa@gmail.com
☺ THANK YOU ☺