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Using a for loop to sum an integer n and call function add_it

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Join Date: Sep 2004

Posts: 2

Reputation: Ginger is an unknown quantity at this point

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Ginger

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Using a for loop to sum an integer n and call function add_it

Sep 27th, 2004

I am to write a program to read a non-negative integer n and call function add_it() to calculate the sum ... If n is 5, the sum 1+2+3... would be computed. n must be less than 8943923. Use a for loop, rather than the summation formula. I am to put main() and add_it() in the same file by calling add_it(). The following is what I have come up with, but I am getting the wrong answer main() {

int main() {
int n,sum; {

printf("Enter a non_negative number to sum:\n");
scanf("%d", &n);

int add_it() {

int n,sum; {
n<8943923;
for (n=0;
n<8943923;
n*(n+1)/2) {
printf("%d\n",n);
sum=n*(n+1)/2;
if (n<8943923) break;
}}}
printf("The summation of %d is %d\n",n,sum);

return(sum);

}}

When I execute the program I get the following:

Enter a non-negative number to sum: (I enter say 20)
The summation of 20 is 4.

This is what I want except the answer should not be 4.

Can anyone help me figure out where I went wrong in this for loop and my equation for getting the sum? Thank you to all who may respond.

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Join Date: Sep 2004

Posts: 220

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frrossk

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Re: Using a for loop to sum an integer n and call function add_it

Sep 27th, 2004

Maybe this will work:

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include <stdio.h>
#include <stdlib.h>
 
int add_it(int n);
 
int main() 
{
int n,sum;
 
printf("Enter a non_negative number to sum:\t");
scanf("%d", &n);
if (n >= 8943923) printf ("n too big\n");
else
{
sum = add_it (n);
printf("The summation of %d is %d\n",n,sum);
}
system ("PAUSE");
}
 
int add_it(int n) 
{
int sum=0, i;
for (i=1; i<=n; i++)
{
printf("%d\n", i);
sum+=i;
}
return sum;
}
#include <stdio.h>
#include <stdlib.h>

int add_it(int n);

int main() 
{
int n,sum;

printf("Enter a non_negative number to sum:\t");
scanf("%d", &n);
if (n >= 8943923) printf ("n too big\n");
else
{
sum = add_it (n);
printf("The summation of %d is %d\n",n,sum);
}
system ("PAUSE");
}

int add_it(int n) 
{
int sum=0, i;
for (i=1; i<=n; i++)
{
printf("%d\n", i);
sum+=i;
}
return sum;
}