Compilare: main.cpp: In function 'void back_track(long long int, long long int, long long int)': main.cpp:25:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos>=div.size()){return;} ~~~^~~~~~~~~~~~ main.cpp: In function 'int32_t main()': main.cpp:71:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<pr.size() && pr[i]<=b; i++){ ~^~~~~~~~~~ main.cpp:87:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<=div.size(); i++){ ~^~~~~~~~~~~~