Compilare: user.cpp: In function ‘bool bfs()’: user.cpp:28:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<grr[vf].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:72:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<grr[d].size();i++) ^ user.cpp:116:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<sol.size();i++) ^ user.cpp:42:9: warning: unused variable ‘m’ [-Wunused-variable] int m; ^