Eroare de compilare: user.cpp: In function ‘int bfs()’: user.cpp:56: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:95: warning: comparison between signed and unsigned integer expressions user.cpp:127: warning: comparison between signed and unsigned integer expressions user.cpp:73: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:75: 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:83: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result In file included from /usr/include/c++/4.4/algorithm:62, from user.cpp:8: /usr/include/c++/4.4/bits/stl_algo.h: In function ‘_FIter std::remove_if(_FIter, _FIter, _Predicate) [with _FIter = std::_Rb_tree_const_iterator<std::pair<int, int> >, _Predicate = bool (*)(const PII&)]’: user.cpp:136: instantiated from here /usr/include/c++/4.4/bits/stl_algo.h:1161: error: passing ‘const std::pair<int, int>’ as ‘this’ argument of ‘std::pair<int, int>& std::pair<int, int>::operator=(const std::pair<int, int>&)’ discards qualifiers