Compilare: main.cpp: In function 'int main()': main.cpp:35:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for(int i=0;i<adj[a].size();i++) | ~^~~~~~~~~~~~~~ main.cpp:67:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for(int i=0;i<pre[a].size();i++) | ~^~~~~~~~~~~~~~ main.cpp:80:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 80 | for(int i=0;i<ans.size();i++) | ~^~~~~~~~~~~ main.cpp:18:17: warning: variable 'nex' set but not used [-Wunused-but-set-variable] 18 | int n,m,x,y,nex; | ^~~