Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:139:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < list[node].size(); i++) ~~^~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘void rm_edge(int)’: user.cpp:174:9: warning: unused variable ‘x’ [-Wunused-variable] int x = E[id].x; ^ user.cpp: In function ‘int main()’: user.cpp:192:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nespus.out","w",stdout); ^ user.cpp: In constructor ‘Buffer::Buffer(std::__cxx11::string, int)’: user.cpp:21:50: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(name.c_str(), "r", stdin); ^ user.cpp: In member function ‘void Buffer::refill()’: user.cpp:63:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(&data[0], 1, dim, stdin); ^