Compilare: user.cpp: In function ‘void df(int, int)’: user.cpp:15:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<gr[x].size();i++) ^ user.cpp: In function ‘void df1(int)’: user.cpp:29:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<gr[x].size();i++) ^ user.cpp:36:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:61:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<gr[vf].size();i++) ^ user.cpp:67:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<gr[vf1].size();i++) ^