pr0520.cpp

practice c++, it is from the book http://www.amazon.com/Schaums-Outline-Programming-John-Hubbard

//  Programming with C++, Second Edition, by John R. Hubbard
//  Copyright McGraw-Hill, 2000
//  Problem 5.20 on page 113
//  The Power Function

#include <iostream>  // defines the cin and cout objects
using namespace std;
double pow(double,int);

int main()
{ cout << "Enter a positive float x and an integer n: ";
  double x;
  int n;
  cin >> x >> n;
  cout << "pow(" << x << "," << n << ") = " << pow(x,n) << endl;
}

double pow(double x, int n)
{ if (x == 0) return 0;
  if (n == 0) return 1;
  double y=1;
  for (int i=0; i < n; i++)
    y *= x;
  for (int i=0; i > n; i--)
    y /= x;
  return y;
}