Compilare: user.cpp: In function ‘std::pair<std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> > > operators(int, int)’: user.cpp:36: warning: suggest explicit braces to avoid ambiguous ‘else’ user.cpp: In function ‘int evaluate(int, int)’: user.cpp:63: warning: comparison between signed and unsigned integer expressions user.cpp:68: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:76: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:77: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:79: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘int answer(char, int, int)’: user.cpp:21: warning: control reaches end of non-void function