where is wrong !! already it is working in codeblocks

#include<stdio.h>

int main(){

int n,sum=0,i;

scanf("%d",&n);-

if(n>0){

sum=(n*(n+1))/2;

}

else if(n<0){

sum=(n*(-1*n+1))/2;

}

printf("%d",sum);

}

Re: where is wrong !! already it is working in codeblocks

Maybe for N < 0 the formula is

SUM = ((2-N)*(N+1))/2

*Edited by author 06.11.2017 19:47*

Re: where is wrong !! already it is working in codeblocks

The first term is N

The last term is 1

So the average is (1+N)/2

There are (-N) terms below zero

And there are two more terms

They are 0 and one

So there are (2-N) total terms

So the sum is average by total number of terms

Re: where is wrong !! already it is working in codeblocks

Case "N == 0" isn't processed

Re: where is wrong !! already it is working in codeblocks

Posted by

jim 22 Feb 2018 07:10

thank you for your hint!

Re: where is wrong !! already it is working in codeblocks

Posted by

WeXoB 20 May 2020 08:51

*Edited by author 20.05.2020 08:52*

*Edited by author 20.05.2020 08:52*