RE: [Dev-C++] weird result

[Ioannis V. <no...@ho...>]

----Original Message-----
From: dev...@li...
[mailto:dev...@li...] On Behalf Of Jose
Gana
Sent: Saturday, June 15, 2002 6:30 PM
To: dev...@li...
Subject: [Dev-C++] weird result



Hi!
Sorry if it is too obvious!

 I am new in C++. I got 2^30= Power(2,30)= - 2147483648 in stead of +
2147483648 in my program.

I must have done something wrong. But I can figure it out. Can somebody
help me out?

 

#include <iostream>

#include <cstdlib>

 

using namespace std;

 

int Power(int a, int n);

 

int main()

{

 int a=2, n=30;           //int limit == 4294967295;

 

Because the int limit isn't that but 2147483647

 

                                    // Power(2,30)==1073741824  

                                  // Power(2,31)==2147483648

                                  // Power(2,32)==4294967296 out of
limit => Power(2,32)==0

 

 cout << "Power(" << a << "," << n << ")= " << Power(a,n) << endl;

 cout << "Power(" << a << "," << n+1 << ")= " << Power(a,n+1) << endl;

 

 system("PAUSE");

 return 0;

}

 

int Power(int a, int n)

{

 int i=1, r=1;

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

 {

 r=r*a;

 }

 return r;

}

 

I am using Dev-C++ version 4.01. in windows XP

Thank you for your help to this matter. 

 
#include <iostream>
#include <cstdlib>
 
double Power(const double a, const double n);
 
 
 
int main()
{
 using namespace std;
 
 int a=2, n=30;           
 
 cout << "Power(" << a << "," << n << ")= " << Power(a,n) << endl;
 
 cout << "Power(" << a << "," << n+1 << ")= " << Power(a,n+1) << endl;
 
 system("PAUSE");
 
 return 0;
 
}
 
 
 
double Power(const double a, const double n)
{
 
 unsigned long i;
 double r;
 
 for (r=i=1;i<=n;i++)
     r=r*a;
 
 return r;
}
 
 
Ioannis

* Ioannis Vranos
* Programming pages: http://www.noicys.cjb.net
<http://www.noicys.cjb.net/> 
* Alternative URL: http://run.to/noicys