#include <stdio.h>

int refsum(int len, int arr[])
{
	int i;
	int sum = 0;
	for (i = 0; i < len; i++) {
		sum += arr[i];
	}
	return sum;
}

int sum(int len, int arr[]);

int main(void)
{
#define LENGTH(x) sizeof(x)/ sizeof(x[0])
	int a[400] = {0};
	int alen = LENGTH(a);
	int b[5] = {5,4,3,2,1};
	int blen = LENGTH(b);

	int i = alen;
	while(i--)
		a[i] = i * b[i%blen];

#define TESTCASE(x,xlen,fkt) \
	printf("%s @ %4s (%-6s):\t%9d\n", #x, #xlen, #fkt, fkt(xlen,x));

	TESTCASE(a, alen, refsum);
	TESTCASE(a, alen, sum);

	TESTCASE(b, blen, refsum);
	TESTCASE(b, blen, sum);

	TESTCASE(b, 0, refsum);
	TESTCASE(b, 0, sum);

	return 0;
}