Compilare: user.cpp: In function ‘void explore(int, long long int)’: user.cpp:13:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (ind == factor.size()) { ~~~~^~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:51:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i ++) ~~^~~~~~~~~~~~ user.cpp:36:9: warning: unused variable ‘nsol’ [-Wunused-variable] int nsol = 1; ^~~~