Here is a list of useful programs compiled by bOtskOOl which might be relevant for you:

1. Complex numbers in C++

#include <cmath>

#include <iostream>

#include <iomanip.h>


using namespace std;

class complex

{

  private:

    float real; // Real Part

  float imag; //  Imaginary Part

  public:

    complex(float, float);

  complex(const complex & );

  complex operator + (complex);

  complex operator - (complex);

  complex operator * (complex);

  complex operator / (complex);

  complex getconjugate();

  complex getreciprocal();

  float getmodulus();

  void setdata(float, float);

  void getdata();

  float getreal();

  float getimaginary();

  bool operator == (complex);

  void operator = (complex);

  friend ostream & operator << (ostream & s, complex & c);

};

//                                        CONSTRUCTOR

complex::complex(float r = 0.0 f, float im = 0.0 f)

{

  real = r;

  imag = im;

}

//                                 COPY CONSTRUCTOR

complex::complex(const complex & c)

{

  this - > real = c.real;

  this - > imag = c.imag;

}

void complex::operator = (complex c)

{

  real = c.real;

  imag = c.imag;

}

complex complex::operator + (complex c)

{

  complex tmp;

  tmp.real = this - > real + c.real;

  tmp.imag = this - > imag + c.imag;

  return tmp;

}

complex complex::operator - (complex c)

{

  complex tmp;

  tmp.real = this - > real - c.real;

  tmp.imag = this - > imag - c.imag;

  return tmp;

}

complex complex::operator * (complex c)

{

  complex tmp;

  tmp.real = (real * c.real) - (imag * c.imag);

  tmp.imag = (real * c.imag) + (imag * c.real);

  return tmp;

}

complex complex::operator / (complex c)

{

  float div = (c.real * c.real) + (c.imag * c.imag);

  complex tmp;

  tmp.real = (real * c.real) + (imag * c.imag);

  tmp.real /= div;

  tmp.imag = (imag * c.real) - (real * c.imag);

  tmp.imag /= div;

  return tmp;

}

complex complex::getconjugate()

{

  complex tmp;

  tmp.real = this - > real;

  tmp.imag = this - > imag * -1;

  return tmp;

}

complex complex::getreciprocal()

{

  complex t;

  t.real = real;

  t.imag = imag * -1;

  float div;

  div = (real * real) + (imag * imag);

  t.real /= div;

  t.imag /= div;

  return t;

}

float complex::getmodulus()

{

  float z;

  z = (real * real) + (imag * imag);

  z = sqrt(z);

  return z;

}

void complex::setdata(float r, float i)

{

  real = r;

  imag = i;

}

void complex::getdata()

{

  cout << "Enter Real:";

  cin >> this - > real;

  cout << "Enter Imaginary:";

  cin >> this - > imag;

}

float complex::getreal()

{

  return real;

}

float complex::getimaginary()

{

  return imag;

}

bool complex::operator == (complex c)

{

  return (real == c.real) && (imag == c.imag) ? 1 : 0;

}

ostream & operator << (ostream & s, complex & c)

{

  s << "Real Part = " << c.real << endl << "Imaginary Part = " << c.imag << endl;

  s << "z = " << c.real << setiosflags(ios::showpos) << c.imag << "i" << endl << resetiosflags(ios::showpos);

  return s;

}

int main()

{

  complex a(10.0 f, -2. f); // Calls Constructor

  cout << a << endl; // Calls the overloaded << operator

  complex b(-2); // Calls Constructor

  complex c = b; // Calls Copy Constructor

  c = a; // calls overloaded = operator

  b.getdata(); // Calls Getdata()

  c.getdata();

  if (b == c) // calls overloaded == operator

    cout << "\nb == c";

  else

    cout << "\nb != c";

  cout << endl << c.getmodulus() << endl; // calls getmodulus function()

  complex d;

  d = a + b;

  cout << d << endl;

  d = a - b;

  cout << d << endl;

  d = a * b;

  cout << d << endl;

  d = a / b;

  cout << d << endl;

  return 0;

}

2. Sort an array

#include<iostream.h>

#include<string.h>

template < class t >

  int sort(t * a, int n)

{

  int flag = 1, i, j;

  t temp;

  for (i = 0; i < n - 1; i++)

  {

    for (j = 0; j < (n - 1 - i); j++)

    {

      if (a[j] > a[j + 1])

      {

        temp = a[j];

        a[j] = a[j + 1];

        a[j + 1] = temp;

        flag = 0;

      }

    }

    if (flag)

      break;

  }

}

int main()

{

  int a[5], n, i;

  cout << "\nenter the size of the array";

  cin >> n;

  cout << "\nenter the elements of integer array ";

  for (i = 0; i < n; i++)

    cin >> a[i];

  cout << "\nelements of the unsorted array are:" << endl;

  for (i = 0; i < n; i++)

    cout << a[i] << "\n";

  sort(a, n);

  cout << "elements of the sorted array array:" << endl;

  for (i = 0; i < n; i++)

    cout << a[i] << "\n";

}

Area and perimeter of rectangle

#include<iostream.h>

#include<string.h>

class shape

{

  protected:

    float inp_perimeter;

  float inp_area;

  public:

    void area();

  void perimeter();

  void show();

};

class rectangle: public shape

{

  float length;

  float breadth;

  public:

    rectangle()

  {

    cout << "\nenter the length";

    cin >> length;

    cout << "\nenter the breadth";

    cin >> breadth;

  }

  void area()

  {

    inp_area = length * breadth;

  }

  void perimeter()

  {

    inp_perimeter = 2 * (length + breadth);

  }

  void show()

  {

    cout << "\narea of rectangle = " << inp_area;

    cout << "\nperimeter of rectangle = " << inp_perimeter;

  }

};

int main()

{

  rectangle r;

  rectangle * ptr[3] = {
    & r,
    & r,
    & r
  };

  int i;

  for (i = 0; i < 3; i++)

    ptr[i] - > area();

  for (i = 0; i < 3; i++)

    ptr[i] - > perimeter();

  for (i = 0; i < 3; i++)

    ptr[i] - > show();

}

4. Program to search an element in a Dynamic Array

int key;

cout << "Enter a value to search for:" << endl;

cin >> key;

int location = search(a, arraySize, key); //function "location" is called 

if (location == -1)

  cout << key << " is not in the array.";

else

  cout << key << " is element " << location << " in the array.";

delete[] a;

cin.ignore(255, '\n');

cin.get();

return 0;

}

int search(int a[], int size, int key)

{

  int i = 0;

  while ((a[i] != key) && (i < size))

    i++;

  if (i == size) //if target is not in a 

    i = -1;

  return i;

}

5. Program to get address of an integer

#include <iostream.h>

using namespace std;

int main()

{

  int xyz;

  cout << & xyz;

}