#include <cstdio>
#include <array>
 
namespace {
	template <size_t N>
	static constexpr auto neighbor_sum (const int (&input)[N]) {
		std::array<int, N> out = {0};
 
		if (N >= 2) {
			out[0] = input[1];
			out[N - 1] = input[N - 2];
 
			for (size_t i = 1; i < (N - 1); ++i) {
				out[i] = input[i - 1] + input[i + 1];
			}
		}
 
		return out;
	}
}
 
int main() {
	for (int v : neighbor_sum({1,3,4,5,0,1,8})) {
		printf("%d ", v);
	}
	puts("");
	return 0;
}

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