Compilare: user.cpp: In function ‘void dfs1(int)’: user.cpp:12:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[k].size();i++) if(v[a[k][i]]==0) dfs1(a[k][i]); ^ user.cpp: In function ‘void dfs2(int)’: user.cpp:18:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<my[k].size();i++) if(x[my[k][i]]==0) dfs2(my[k][i]); ^ user.cpp: In function ‘int main()’: user.cpp:46:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<c[i].size();j++) ^