Compilare: user.cpp: In function ‘void DF(int)’: user.cpp:17:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[nod].size();i++) ^ user.cpp: In function ‘void DF2(int)’: user.cpp:24:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<b[nod].size();i++) ^ user.cpp: In function ‘void DF3(int)’: user.cpp:30:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:54:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<l.size();i++) ^ user.cpp:62:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<st.size();i++) ^ user.cpp:65:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<st.size();i++) ^