#include <stdio.h>

#define NUM_ELEMS	100

int sum (int n)
{ 
    int i;
    int sum = 0;

    for (i = 0; i <= n; i++)
        sum += i;

    return sum; 
} 

int main ()
{
    int result = sum (NUM_ELEMS);

    printf ("result = %d\n", result);
    printf ("easier computation = %d\n", (NUM_ELEMS*(NUM_ELEMS+1)>>1));
}