Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:17:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();i++){ ^ user.cpp: In function ‘void dfs1(int, int)’: user.cpp:28:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();i++){ ^ user.cpp: In function ‘void dfs2(int)’: user.cpp:42:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();i++){ ^