Compilare: user.cpp: In function ‘bool bfs()’: user.cpp:30:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[node].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:67:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[(n<<1)|1].size();++i) ^ user.cpp:90:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<sol[i].size();++j) ^ user.cpp:46:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harta.in","r",stdin); ^ user.cpp:47:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("harta.out","w",stdout); ^ user.cpp:49:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:52:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^