#include <iostream>
 
signed sum_range1(signed count)
{
	signed accu = 0;
	for (signed i = 0; i <= count; ++i) accu += i;
	return accu;
}
 
unsigned sum_range2(unsigned count)
{
	unsigned accu = 0;
	for (unsigned i = 0; i != count + 1; ++i) accu += i;
	return accu;
}
 
signed sum_array_evens1(signed * array, signed len)
{
	signed accu = 0;
	for (signed i = 0; i < len; i += 2) accu += array[i];
	return accu;
}
 
unsigned sum_array_evens2(unsigned * array, unsigned len)
{
	unsigned accu = 0;
	for (auto cur = array, last = array + len; cur < last; cur += 2) accu += *cur;
	return accu;
}
 
int main()
{
	signed array1[] = {1, 2, 3, 4};
	unsigned array2[] = {1, 2, 3, 4};	
 
	std::cout << "sum_range1(100): ";
	std::cout << sum_range1(100) << "\n";
	std::cout << "sum_range2(100): ";
	std::cout << sum_range2(100) << "\n";
	std::cout << "sum_array_evens1(array1, 3): ";
	std::cout << sum_array_evens1(array1, 3) << "\n";
	std::cout << "sum_array_evens2(array2, 3): ";
	std::cout << sum_array_evens2(array2, 3) << "\n";
	std::cout << "sum_array_evens1(array1, 4): ";
	std::cout << sum_array_evens1(array1, 4) << "\n";
	std::cout << "sum_array_evens2(array2, 4): ";
	std::cout << sum_array_evens2(array2, 4) << "\n";
}

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