Compilare: user.cpp: In function ‘int main()’: user.cpp:46:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<sol.size() - 1; i++){ ~^~~~~~~~~~~~~~~ user.cpp:47:42: warning: variable ‘a’ set but not used [-Wunused-but-set-variable] int it = sol[i], it2 = sol[i+1], a, b; ^ user.cpp:47:45: warning: variable ‘b’ set but not used [-Wunused-but-set-variable] int it = sol[i], it2 = sol[i+1], a, b; ^ user.cpp:54:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (sol.size() != n) return cout << 0, 0; ~~~~~~~~~~~^~~~