[ c++] fibonacci series By me

Fibonacci number on Wiki

http://en.wikipedia.org/wiki/Fibonacci_number

Attachment 12368

Code:

---

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

int power(int a, int b)
{
    int c=a;
    for (int n=b; n>1; n--) c*=a;
    return c;
}

double power(double a, int b)
{
      float c=a;
      for (int n=b; n>1; n--) c*=a;
      return c;
}

int main()
{

double first,c1,c2,r1,r2,r3; int r,l;

    first=0.4472135955;  c1=1.618033989; c2=-0.6180339887;

cout<< " Enter  long The series ";
cin>>l;

        for (int i=1; i<l; i++)

        {
          r1=power(c1,i);
          r2=power(c2,i);
          r3= r1-r2;
          r= first*r3;
          cout<<r<<",";
        }
        cout <<endl;
    system("pause");
    return 0;
}

---

You forgot to ask a question, such as why the results you're getting are incorrect.
Using a float inside your double version of power would be one mistake.
Also, seeing as how you're limiting yourself to the range of ints anyway, you aren't gaining anything by using the approximation method.