Compilare: main.cpp: In function 'int main()': main.cpp:90:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<ev[i].size();j++) ~^~~~~~~~~~~~~ main.cpp:95:18: warning: unused variable 'j' [-Wunused-variable] for(auto j:ev[i]) ^ main.cpp:146:18: warning: unused variable 'j' [-Wunused-variable] for(auto j:ev[i]) ^ main.cpp:191:14: warning: variable 'ok' set but not used [-Wunused-but-set-variable] bool ok=0; ^~