Compilare: user.cpp: In function ‘void solve(long long unsigned int)’: user.cpp:36:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i <= k; i++) ^ user.cpp:40:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i > k) ^ user.cpp:46:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = i + 1; i <= k; i++) ^ user.cpp: In function ‘int main()’: user.cpp:77:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= K; i++) ^