Compilare: user.cpp: In function ‘void dragon(int)’: user.cpp:22:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[b].size();i++) ^ user.cpp: In function ‘int dist(int)’: user.cpp:46:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[b].size();i++) ^ user.cpp:74:1: warning: control reaches end of non-void function [-Wreturn-type] } ^