C++ Programming

C++ hello world example

#include<iostream>
using namespace std; 
int main()
{
 cout << "Hello World\n";
 return 0;
}

Addition

#include <iostream> 
using namespace std; 
int main()
{
   int a, b, c;
   cout << "Enter two numbers to add\n";
   cin >> a >> b;
   c = a + b;
   cout <<"Sum of entered numbers = " << c << endl;
   return 0;
}

C++ program to reverse a number

#include <iostream>
using namespace std; 
class Operations
{
  long c;
 
public:
  void inputNumber()
  {
    cout << "Input a number\n";
    cin >> c;
  }
  long reverseNumber()
  {
    long invert = 0;
    while (c != 0)
    {
      invert = invert * 10;
      invert = invert + c%10;
      c = c/10;
    }
    return invert;
  }
 };
int main()
{
  long result;
 
  Operations t;
  t.inputNumber();
  result = t.reverseNumber();
 
  cout << "Number obtained on reversal = " << result;
  return 0;
}

Program To find prime number

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
   int n, status = 1, num = 3, count, c;
   cout << "Enter the number of prime numbers to print\n";
   cin >> n;
   if ( n >= 1 )
   {
      cout << "First " << n <<" prime numbers are :-" << endl;
      cout << 2 << endl;
   }
 
   for ( count = 2 ; count <=n ;  )
   {
      for ( c = 2 ; c <= (int)sqrt(num) ; c++ )
      {
         if ( num%c == 0 )
         {
            status = 0;
            break;
         }
      }
      if ( status != 0 )
      {
         cout << num << endl;
         count++;
      }
      status = 1;
      num++;
   }         
   return 0;
}

 Adding two arrays

include<iostream>
using namespace std;
 
main()
{
   int first[20], second[20], c, n;
   cout << "Enter the number of elements in the array ";
   cin >> n;
   cout << "Enter elements of first array " << endl;
   for ( c = 0 ; c < n ; c++ )
      cin >> first[c];
   cout << "Enter elements of second array " << endl;
   for ( c = 0 ; c < n ; c++ )
      cin >> second[c];
   cout << "Sum of elements of two arrays " << endl;
   for ( c = 0 ; c < n ; c++ )
      cout << first[c] + second[c] << endl;
   return 0;
} 

Simple Class Program

#include<iostream>
using namespace std;
 
class programming
{
   private:
      int variable;
 
   public:
 
      void input_value()
      {
         cout << "In function input_value, Enter an integer\n";
         cin >> variable;
      }
      void output_value()
      {
         cout << "Variable entered is ";
         cout << variable << "\n";
      }
};
 
main()
{
   programming object;
   object.input_value();
   object.output_value();
   //object.variable;  Will produce an error because variable is private
   return 0;
}

Program to Convert Deci to Binary

#include<iostream>
#include <stdio.h>
using namespace std;


int main()
{
  int n,x,a, c, k;


  cout<<"Enter an integer in decimal number system";
  cin>>x;
  n=x;
  cout<<"Binary Value OF Given Number Is: ";
 for( a=1;n!=0;a++)
  {
     n=n/2;
  }
a=a-2;
  for (c = a; c >= 0; c--)
  {
    k = x >> c;
    if (k & 1)
      cout<<"1";
    else
      cout<<"0";
  }
  return 0;
}

Program To add  2x2 matrices

#include<iostream>

using namespace std;


int main(){

//Using const int for array size
    const int row=2,col=2;
// if not use const error found

cout<<"Size of Matrices : "<<row<<" X "<<col<<endl;
cout<<"Enter Value For First Matrix:"<<endl;
int first[row][col], second[row][col];
int i,j;
for( i=0;i<row;i++){
    cout<<"Enter value for row number: "<<i+1<<endl;
    for( j=0;j<col;j++){
        cin>>first[i][j];
    }
}
cout<<"\n\n\nEnter Value For Second Matrix:"<<endl;
for( i=0;i<row;i++){
    cout<<"Enter value for row number: "<<i+1<<endl;
    for( j=0;j<col;j++){
        cin>>second[i][j];
    }
}
// Resultant Matrix
for( i=0;i<row;i++){
    for( j=0;j<col;j++){
        first[i][j]=first[i][j]+second[i][j];
    }
}
cout<<"\n\n\t\tResultant Matrix:"<<endl;
for( i=0;i<row;i++){
    cout<< endl;
    for( j=0;j<col;j++){
        cout<<"\t\t"<<first[i][j]<<"    ";
    }
}
return 0;
}