Compilare: user.cpp: In function ‘bool validate(int)’: user.cpp:24:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(jlast>=x[last] && last!=n) ^ user.cpp: In function ‘void solve()’: user.cpp:60:23: warning: format ‘%i’ expects argument of type ‘int’, but argument 2 has type ‘long long unsigned int’ [-Wformat=] printf("%i\n", sol); ^