Compilare: user.cpp: In function ‘bool path()’: user.cpp:34:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[q0].size() ; ++i) ^ user.cpp: In function ‘int main()’: user.cpp:82:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0 ; j < g[d].size() ; ++j) ^ user.cpp:48:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("album.in" , "r" , stdin); ^ user.cpp:49:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("album.out" , "w" , stdout); ^