Compilare: user.cpp: In function ‘int main()’: user.cpp:63:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (auto i = 0u; i < N; i++) { ^ user.cpp: In function ‘int binary_search0(const std::vector<int>&, int, int, int)’: user.cpp:21:15: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (V[last] == x) return last; ^ user.cpp: In function ‘int binary_search1(const std::vector<int>&, int, int, int)’: user.cpp:36:12: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return last; ^ user.cpp: In function ‘int binary_search2(const std::vector<int>&, int, int, int)’: user.cpp:50:12: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] return last; ^ user.cpp: In function ‘int main()’: user.cpp:82:60: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] out << binary_search2(V, 0, V.size(), x) + 1 << std::endl; ^ user.cpp:79:60: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] out << binary_search1(V, 0, V.size(), x) + 1 << std::endl; ^