Compilare: user.cpp: In function ‘db getsol(std::vector<std::pair<int, int>, std::allocator<std::pair<int, int> > >)’: user.cpp:34: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result