Compilare: user.cpp: In function ‘void Biconex(int, int, int)’: user.cpp:29:9: warning: unused variable ‘x’ [-Wunused-variable] int x; ^ user.cpp: In function ‘int main()’: user.cpp:64:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); ++i) ^ user.cpp:68:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < sol[i].size(); ++j) fout << sol[i][j] << " "; ^