Compilare: user.cpp: In function ‘void topsort(int)’: user.cpp:23:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[head].size(); i++) ^ user.cpp: In function ‘void dfs(int)’: user.cpp:31:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<vv[head].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:48:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<sol[i].size(); j++) ^