?
Solved

writing a function

Posted on 2000-03-01
6
Medium Priority
?
222 Views
Last Modified: 2010-04-15
Write the function odd_sum that accepts a positive integer N as a parameter and returns the sum of the first N odd numbers. A call to odd_sum of the form:

           sum = odd_sum(5);

will return the value 25 since 1+3+5+7+9=25

thank in advance!
0
Comment
Question by:beachbumm
  • 3
  • 2
6 Comments
 
LVL 16

Accepted Solution

by:
imladris earned 100 total points
ID: 2573009
int odd_sum(int n)
{   int i,sum;

    sum=0;
    for(i=1; i<n*2; i+=2)sum+=i;
    return(sum);
}
0
 
LVL 31

Expert Comment

by:Zoppo
ID: 2573109
or, simple and fast

int odd_sum( int n )
{
 return (n*n);
}

ZOPPO
0
 
LVL 31

Expert Comment

by:Zoppo
ID: 2573133
Proof:

sum <0...n> (2n + 1) =
sum <0...n> (2n)   + sum <0...n> (1) =
2((n*(n+1))/2)     + (n+1) =
n*n + 2n + 1 =
(n+1)*(n+1)

so, odd_sum(5) = sum<0...4>(2n+1) = n*n                           :o)

ZOPPO
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 
LVL 18

Expert Comment

by:deighton
ID: 2573134

*/optimized code/*

int odd_sum(int n)
{
        return n * n;
}
0
 
LVL 18

Expert Comment

by:deighton
ID: 2573138
oops zoppo already thought of that.
0
 
LVL 31

Expert Comment

by:Zoppo
ID: 2573141
sorry, meant 5*5 instead of n*n in last line .....
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

An Outlet in Cocoa is a persistent reference to a GUI control; it connects a property (a variable) to a control.  For example, it is common to create an Outlet for the text field GUI control and change the text that appears in this field via that Ou…
Examines three attack vectors, specifically, the different types of malware used in malicious attacks, web application attacks, and finally, network based attacks.  Concludes by examining the means of securing and protecting critical systems and inf…
The goal of this video is to provide viewers with basic examples to understand and use conditional statements in the C programming language.
The goal of this video is to provide viewers with basic examples to understand and use switch statements in the C programming language.

749 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question