Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[x].size();i++) ^ user.cpp: In function ‘void dfstrans(int)’: user.cpp:30:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a1[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:66:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<sol[i].size();j++) ^