Compilare: main.cpp: In function 'std::vector<long long int> sortaretopologica(std::vector<std::vector<long long int> >&)': main.cpp:12:14: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::vector<long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 12 | for(i=0;i<vec.size();i++)for(ll x:vec[i])deg[x]++; | ~^~~~~~~~~~~ main.cpp:13:14: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 13 | for(i=0;i<deg.size();i++)if(deg[i]==0)bfs.push(i),ok[i]=1,cerr<<i<<' '; | ~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:27:18: warning: unused variable 'j' [-Wunused-variable] 27 | ll n,m,a,b,i,j; | ^