Compilare: user.cpp: In function ‘std::pair<int, int> ChainEndNodes(int)’: user.cpp:110:9: warning: variable ‘last_k’ set but not used [-Wunused-but-set-variable] int last_k = x, last_nd = x, last_2 = x; ^ user.cpp: In function ‘std::pair<int, int> DistanceDNodes(int, int)’: user.cpp:230:9: warning: variable ‘last_k’ set but not used [-Wunused-but-set-variable] int last_k = x, last_nd = x, last_2 = x; ^ user.cpp: In function ‘int main()’: user.cpp:383:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, op, x, y, D; ^ user.cpp:383:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, op, x, y, D; ^