DaniWeb Forum Index > Software Development > C++

C++ RSS

stuck

Please support our C++ advertiser: Intel Parallel Studio Home

•

Join Date: May 2008

Posts: 29

Reputation: wellibedamned is an unknown quantity at this point

Solved Threads: 0

wellibedamned wellibedamned is offline

Offline

Light Poster

stuck

May 25th, 2008

could someone please check this code and tell me where i went wrong... it always gives the result 1.00000 but as you can see in the for loop it shouldn't be like that.

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <cstdio>
int main(void)
{
    int n;
    float s = 0;
    scanf("%d", &n);
    for(int i = 1; i <= n; i++)
            {
            if(i % 2 == 0) s -= 1/(i*i);
            else s += 1/(i*i);    
            }            
    printf("%1.5f", s);
    scanf("\n");
    return 0;
}
#include <cstdio>
int main(void)
{
    int n;
    float s = 0;
    scanf("%d", &n);
    for(int i = 1; i <= n; i++)
            {
            if(i % 2 == 0) s -= 1/(i*i);
            else s += 1/(i*i);    
            }            
    printf("%1.5f", s);
    scanf("\n");
    return 0;
}

•

Join Date: Oct 2007

Posts: 1,953

Reputation: Duoas has much to be proud of

Solved Threads: 214

Duoas

Offline

Posting Virtuoso

Re: stuck

May 25th, 2008

You need to be working with floats on the right-hand side to get floating-point division. Right now you are doing integer divisions.
s -= 1.0/(i*i);

This one gets everyone at least once a year. Hope this helps.

•

Join Date: May 2006

Posts: 248

Reputation: hammerhead is an unknown quantity at this point

Solved Threads: 24

hammerhead hammerhead is offline

Offline

Posting Whiz in Training

Re: stuck

May 25th, 2008

Typecasting worked for me

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
  if(i % 2 == 0) s -= 1/(float)(i*i);
            else s += 1/(float)(i*i);
  if(i % 2 == 0) s -= 1/(float)(i*i);
            else s += 1/(float)(i*i);